Morphological and molecular updates of Corynosoma bullosum (Linstow, 1892) Raulliet & Henry, 1907 parasitizing southern elephant seals from the Antarctic Peninsula

Morphological and molecular updates of Corynosoma bullosum (Linstow, 1892) Raulliet & Henry, 1907 parasitizing southern elephant seals from the Antarctic Peninsula | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Morphological and molecular updates of Corynosoma bullosum (Linstow, 1892) Raulliet & Henry, 1907 parasitizing southern elephant seals from the Antarctic Peninsula Florencia A. Soto, Sara M. Rodríguez, María S. Leonardi, Javier Negrete, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-1879398/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background: Previous descriptions of Corynosoma bullosum (Linstow, 1892) Railliet & Henry, 1907 show that the specimens vary greatly for the proportions of the different structures of the body, measurements of females and males, number of rows of hooks, egg measurements, among others. Here, we redescribe this species from specimens found in the southern elephant seal ( Mirounga leonina ) feces, from 25 de Mayo/King George Island. We also provide a molecular characterization, in addition to 5.8s and ITS existing sequences. Results: We examined feces collected from 41 elephants in 2016 and 2018. We found 30 adult acanthocephalans in 15 of them (19 females and 11 males). The specimens were identified as belonging to the genus Corynosoma due to the tubular body with an inflated anterior part forming a thorny disk and the posterior part bearing somatic spines on the ventral surface, and genital spines surrounding the genital pore. The morphology of the individuals corresponded to C. bullosum : large size, marked sexual dimorphism (females 13.7-20.0mm and males 9.5-13.6mm in length), and proboscis with 16-18 rows of spines with 11-15 spines per row (8-12 apical and 3-4 basal). The molecular profile of two specimens of C. bullosum was analysed using cytochrome oxidase 1 (COI). Finally, we inferred phylogenetic relationships of the family Polymorphidae using maximum likelihood (ML) and Bayesian inference (BI). Conclusions: We provided an updated morphological redescription for C. bullosum including electron microscopy photographs and molecular data. We also present a summary table showing the great morphological variation of the species. The COI gene sequences revealed that C. bullosum has low genetic variation and that this species is more closely related to Andracantha sigma than to the genus Corynosoma . Our analyses show that it is necessary to perform a phylogenetic study of the family Polymorphidae including all the species. Acanthocephala Corynosoma bullosum cytochrome oxidase 1 Mirounga leonina Polymorphidae Figures Figure 1 Figure 2 Figure 3 Background The acanthocephalan genus Corynosoma includes species from the gastrointestinal tract of pinnipeds [ 1 ], thirteen of which parasitize seals and fur seals worldwide [ 1 , 2 ]. Some of these species have been described in Antarctic and sub-Antarctic pinnipeds, e.g. C. hamanni (Linstow, 1892), C. bullosum (Linstow, 1892), C. australe Johnston, 1937, C. arctocephali Zdzitowiecki, 1984, C. hannae Zdzitowiecki, 1984, C. pseudohamanni Zdzitowiecki, 1984, C. evae Zdzitowiecki, 1984 and C. gibsoni Zdzitowiecki, 1986 (Table 1 ). Particularly, the southern elephant seal, Mirounga leonina , has been reported as the only suitable definitive host for C. bullosum . A questionable record indicates the northern elephant seal, M. angustrirostris , as another suitable definitive host [ 1 ]. In addition, larval stages of C. bullosum were found in the sperm whale, probably as an unsuitable definitive host [ 1 ]. Larval specimens were also found in the intestine of seabirds, such as the cormorant and the gentoo penguin [ 1 ]. Table 1 Different Corynosoma species described in Antarctic and sub-Antarctic pinnipeds; * Unsuitable definite host, (?) Questionable report. Corynosoma species Host Locality Reference C. hamanni Hydrurga leptonyx Leptonychotes weddelli Lobodon carcinophaga* South Shetlands [ 1 , 3 , 31 ] C. bullosum Mirounga leonina Mirounga angustirostris (?) Hydrurga leptonyx* Leptonychotes weddelli* , Lobodon carcinophaga* South Shetlands [ 1 , 3 , 5 , 14 ] C. australe Hydrurga leptonyx Otaria flavescens South Shetlands Patagonia Argentina [ 1 , 32 , 33 , 34 ] C. arctocephali Arctocephalus gazella Hydrurga leptonyx Lobodon carcinophaga* South Shetland [ 1 , 33 ] C. hannae Hydrurga leptonyx South Shetland [ 33 ] C. pseudohamani Leptonychotes weddelli Lobodon carcinophaga Hydrurga leptonyx* Mirounga leonina* Arctocephalus gazella* South Shetlands [ 1 , 31 ] C. evae Hydrurga leptonyx Otaria flavescens South Shetlands Patagonia Argentina [ 1 , 33 ] C. gibsoni Otaria flavescens Malvinas Islands [ 34 ] The acanthocephalan C. bullosum was first described by Linstow in 1892 [ 3 ]; from elephant seals in South Georgia. Since this first description, several later findings and reports have been mentioned below. The different available descriptions for the species present several discrepancies in the measurements, principally in total body length, the number of rows of hooks, and the number of hooks per row [ 1 , 4 , 5 , 6 ]. The report by Johnston & Edmonds 1953 [ 4 ] briefly described the species based on a single female specimen found in the intestine of an elephant seal on the Campbell and Auckland Islands. On an Antarctic expedition in 1949, Edmonds et al. (1954) [ 5 ] obtained several acanthocephalans in the Heard Islands that allowed them to give several measurements. Later, in a morphological description carried out by Zdzitowiecki 1986 [ 6 ] measurements of 20 females and 20 males were given, which were recovered from the intestine of three elephant seals from the South Shetland Islands. At present, the contribution of Laskowski and Zdzitowiecki (2017) [ 1 ] constitutes the complete study of the morphology of Corynosoma species from Antarctica and the sub-Antarctic region. They also provide a list of suitable and unsuitable definitive hosts, as well as paratenic and intermediate hosts. On the other hand, phylogenetic analysis of the genera Corynosoma based on ITS and 5.8s rRNA sequences supported the monophyly of the family and some of their genera [ 7 ]. However, considering the discrepancies in the morphological descriptions and the absence of a correlation between molecular and morphological data, this work provides a morphological and molecular update of C. bullosum. Materials And Methods Specimens collection During the reproductive seasons of 2016/2017 and 2017/2018, 29 specimens of acanthocephalans were collected from fecal samples from 41 southern elephant seals, Mirounga leonina Linnaeus, 1758 (Pinnipedia, Phocidae). The fieldwork was conducted in the Antarctic Specially Protected Area ASPA N°132, “Península Potter”, near the Argentinean Scientific Base “Dr. Alejandro Carlini”, 25 de Mayo/King George Island (62°14’S 51 58°40’W) (Fig. 1 ). Fecal samples were obtained directly from the ground, very close to the animals. To avoid contamination, we collected only the top of the feces. Animals showed no signs of illness at the time of collection and all feces samples were fresh. The samples were frozen at -20°C and then examined under a stereomicroscope. Parasites were collected, placed in distilled water, and repeatedly washed; subsequently, they were individually preserved in 96% ethanol. We also checked fecal samples from eight Weddell seals ( Leptonychotes weddellii ) and one crabeater seal ( Lobodon carcinophaga ) but we did not find any acanthocephalan. Morphological study Some selected specimens (10 females and 10 males in good condition) were cleared in lactic acid and studied under a light microscope (Leica DM 2500) for morphological description. Measurements were taken using the Leica Application Suite microscope software. For scanning electron microscopy (SEM), a female and a male were gradually dehydrated in an ethanol series, immersed in hexamethyldisilazane for 15 min, and air-dried for 10 min. Photomicrographs of a female and a male were obtained with a Jeol JSM-6460LV SEM operating at 15 kV (Fig. 2 ). All the measurements are in millimetres unless otherwise stated (Table 2 ). The number of hooks per row was determined in all the specimens by counting in 4 neighbouring rows, following Zdzitowiecki (1986). Vouchers were deposited at the Parasitological Collection of the Instituto de Biología de Organismos Marinos, Puerto Madryn, Chubut province, Argentina (CNP-Par 197 and CNP-Par 198). Table 2 Comparative measurements of Corynosoma bullosum from southern elephant seal; measures in millimetres mean and range in parenthesis. *The author did not differ by sex. Reference Linstow (1892) Edmonds (1954) Zdzitowiecki (1986) Present study Host Mirounga leonina Mirounga leonina Hydrurga leptonyx Mirounga leonina Lobodon carcinophaga Mirounga leonina Locality South Georgia Heard and Macquarie Islands South Shetlands Potter Cove n Not specific 100 40 20 General Number of rows of hooks 25 15–16 16–18 16–18 Number of hooks per row 8 11–13 10–15 11–15 Number apical hooks per row 8–9 7–11 8–12 Number basal hooks per row 3–4 2–4 3–4 Female Body length 15 13.3 13.6–19.7 17.1(13.7–20.0) Trunk dimensions 2.17 1.9 12.01-17.8x1.8-2.8 12.7-18.1x2.0-2.9 Proboscis length 0.94–1.10* 1.11–1.33 1.21(1.15–1.27) Proboscis width 0.26* 0.34–0.40 0.39(0.32–0.45) Proboscis receptacle (length to width) 1.4x0.30* 1.87-2.27x0.37-0.55 1.75-1.82-x0.43-0.55 Largest hook 0.087* 0.099-0120 0.11(0.093–0.123) Neck dimensions (length to width) 0.4 length* 0.45–0.62 length 0.43x0.55 Lemnisci 1.13-1.70x0.70-1.25 1.03-1.50x0.59-1.12 Genital complex (length) 3.5 length 2.5–3.4 3.1(2.6–3.2) Genital spines 3-120 5-115 Eggs (length to width) 0.13x0.03 0.10x0.02 0.107-0.125x0.035-0.039 0.112-0.123x0.033-0.035 Male Body length 7 7.3 9.6–13.4 12.8(9.5–13.6) Trunk dimensions 1.97 1.6 8.0-11.7x1.4-2.0 7.9-11.3x1.3-1.9 Proboscis length 0.94–1.10* 0.91–1.35 1.11(0.90–1.15) Proboscis width 0.26* 0.31–0.37 0.29(0.28–0.33) Proboscis receptacle (length to width) 1.4x0.30* 1.63-2.22x0.27-0.51 1.36-1.66x0.25-0.45 Largest hook 0.087* 0.089-0117 0.109(0.093–0.123) Neck dimensions (length to width) 0.4 length* 0.37–0.48 length 0.33x0.43 Lemnisci 0.85-1.54x0.57-0.90 0.80-1.40x0.47-0.77 Right testis (length to width) 0.7-0.9x0.32-0.45 0.78-1.51x0.32-0.71 0.73-1.33x0.35-0.50 Left testis (length to width) 0.68-1.62x0.41-0.69 0.70-1.53x0.37-0.55 Genital spines 80–250 90–230 Cements glands 6 6 6 Evert copulatory pouch 1.08x0.99 0.94x0.83 Molecular study Genetic comparison and phylogenetic analyses were based on a fragment of 631 bp of the mitochondrial cytochrome oxidase I (COI) gene. Sequences of two individuals of Coryonsoma bullosum from the southern elephant seal, Mirounga leonina , from Península Potter, Antarctic Peninsula, were analysed. The samples were digested overnight at 55°C and genomic DNA was isolated using a commercial extraction kit (Wizard® Genomic DNA Purification Kit, Promega, Madison, WI, USA). A fragment of the COI gene was amplified using the primers detailed by Folmer et al. [ 8 ] following the protocol of Amin et al. (2019) [ 9 ]. Amplicons were sequenced using an external sequencing service (Macrogen, Inc., Seoul, South Korea). The new DNA sequences were edited using Codon-Code (Codon Code Aligner, Dedham, Massachusetts) and deposited in GenBank (OP142751-OP142752). The new COI sequence was integrated into a matrix with one representative of each genus of the family Polymorphidae. A total of 42 belonging to the family Polymorphidae were downloaded from GenBank (Table 4 ) and analysed. In addition, we used as outgroup the phylogenetically related species Plagiorhynchus cylindraceus and Centrorhynchus globocaudatis (Plagiorhynchidae), and Sphaerirostris lanceoides (Centrorhynchidae). As such, the analysed matrix has a total of 45 sequences. Sequence alignment was done in Clustal as implemented in MEGA 7 [ 10 ] using the default parameter values. Observed genetic distance ( p ) between haplotypes and sample pairs were calculated in MEGA 7. jModelTest was used to select the model of nucleotide substitution (GTR + G + I). Two methods of phylogenetic inference were implemented, Maximum Likelihood (ML) and Bayesian inference (BI). The ML analysis was conducted with IQ-TREE using the online implementation W-IQ-TREE ( https:/iqtree.cibiv.univie.ac.at ; [ 11 , 12 ]), with perturbation strength set to 0.5 and stopping rule set to 100. Clade support was calculated with 1,000 ultrafast bootstrap pseudo-replications (BS). The BI analysis was conducted with MrBayes 3.1 [ 13 ] with two independent runs with four heated and one cold Markov chain each. Runs lasted 20 million generations and parameters and trees were sampled every 1,000 generations. Model parameters were estimated in MrBayes. Convergence to stable log-likelihood values was checked by plotting log-likelihood values against generation time. The first 25% of the tree sampled were discarded as burn-in; the remaining trees, all from the convergence zone, were used to compute 50% majority rule consensus trees and to obtain posterior probability (PP) values for each clade. Results In Table 2 , we summarise the comparative measurements of females and males of the acanthocephalan Corynosoma bullosum from the southern elephant seal, given by the different authors and the present data. Morphological data of Corynosoma bullosum (Linstow, 1892) The presence of 16–18 rows of hooks with 11–15 hooks each one (8–12 anterior and 3–4 basal hooks some rootless) are the diagnosis characteristics for C. bullosum . Specimens are white, great size, and with evident sexual dimorphism. Females are larger than males. Hind-trunk cylindrical, longer than fore-trunk. The trunk expands anteriorly forming a disc; spines spread ventrally. Genital spines surround the genital pore in both sexes. Lemnisci are flat and equal in size, shorter than proboscis receptacle. Hooks' measurements are given in Table 3 . Females: Fore-trunk constitutes 20–30% of trunk length. Somatic armature covers 30–40% of trunk length on the ventral side. Genital pore terminal. Males: Fore-trunk constitutes 25–35% of trunk length. Somatic armature covers 35–50% of trunk length on the ventral side. Table 3 Dimensions of proboscis hooks of Corynosoma bullosum from southern elephant seal based on four neighboring rows of hooks in 10 females and 10 males; measures in millimetres mean and range in parenthesis. Hook N° Female Male Thorn length Basal width Root length Thorn length Basal width Root length Apical 1 0.108(0.093–0.123) 0.029(0.027–0.032) 0.094(0.091–0.097) 0.074(0.065–0.08) 0.022(0.019–0.025) 0,064(0.061–0.067) Apical 2 0.092(0.087–0.099) 0.027(0.023–0.030) 0.077(0.075–0.079) 0.059(0.057–0.063) 0,021(0.017–0.027) 0.059(0.057–0.061) Apical 3 0.088(0.084–0.098) 0.025(0.022–0.029) 0.076(0.074–0.078) 0.060(0.058–0.062) 0.022(0.018–0.026) 0.059(0.058–0.061) Apical 4 0.089(0.084–0.094) 0.026(0.024–0.029) 0.072(0.071–0.074) 0.059(0.057–0.062) 0.021(0.018–0.025) 0.058(0.056–0.060) Apical 5 0.086(0.081–0.091) 0.029(0.026–0.032) 0.072(0.070–0.075) 0.059(0.056–0.063) 0.022(0.016–0.026) 0.057(0.055–0.059) Apical 6 0.083(0.081–0.085) 0.029(0.025–0.032) 0.073(0.071–0.074) 0.059(0.056–0.062) 0.020(0.017–0.024) 0.056(0.054–0.058) Apical 7 0.082(0.081–0.084) 0.031(0.028–0.033) 0.075(0.073–0.077) 0.058(0.055–0.062) 0.021(0.018–0.023) 0.055(0.053–0.057) Apical 8 0.081(0.078–0.083) 0.030(0.028–0.032) 0.079(0.075–0.082) 0.057(0.054–0.060) 0.019(0.017–0.022) 0.053(0.051–0.056) Apical 9 0.079(0.078–0.080) 0.030(0.027–0.033) 0.080(0.078–0.083) 0.055(0.052–0.058) 0.019(0.017–0.021) 0.052(0.049–0.055) Basal 1 0.065(0.064–0.066) 0.020(0.018–0.021) 0.045(0.042–0.049) 0.039(0.037–0.040) Basal 2 0.065(0.061–0.069) 0.016(0.013–0.019) 0.046(0.045–0.048) 0.039(0.037–0.041) Basal 3 0,062(0.060–0.063) 0.014(0.013–0.015) 0.046(0.045–0.047) 0.039(0.037–0.040) Molecular results Both phylogenetic trees gathered via ML and BI were mostly congruent (Fig. 3 ). The Polymorphidae family was found to be monophyletic and with high support (PP = 0.99; BS = 69). Within the Polymorphidae clade, three lineages were found. One of these is the highly supported clade (PP = 1; BS = 97) formed by the genera Andracantha, Bolbosoma , and Corynosoma , where Bolbosoma is the single genus found in monophyletic (PP = 1; BS = 99). The genus Bolbosoma is sister to a clade (PP = 0.81; BS = 77) formed by all the species of Corynosoma (PP = 0.99; BS = 89) except Corynosoma bullosum , which is sister (PP = 1; BS = 100) to Andracantha sigma and not to Corynosoma clade (Fig. 3 ). The other lineage is formed by Polymorphus, Arhytmorhynchus, Profilicollis, Pseudocorynosoma, Tenuisoma, Hexaglandula , and Ibirhynchus genera, which appears well supported only in the BI analysis (PP = 0.81; BS = 48). The third lineage is formed by Arhytmorhynchus, Polymorphus , and Southwellina , which form a high supported clade (PP = 1; BS = 99; Fig. 3 ). The genealogical analysis showed that our sequences from the southern elephant seal, fall in the C. bullosum clade (PP = 1; BS = 100; Fig. 3 ). Haplotypes of C. bullosum show extremely low genetic variation (0.7%). Both haplotypes differ from A. sigma by 10%. Sequences of C. bullosum with clades formed by Andracantha and Bolbosoma members differ on average by 19%. Compared with the clade formed by Corynosoma members, sequences of C. bullosum differ by 21%. The average genetic p -distances between the clade of C. bullosum and the lineage formed by the genera Arhythmorhynchus, Polymorphus, Profilicollis, Pseudocorynosoma, Tenuisoma, Hexaglandula , and Ibirhynchus differ by 25%, and the genetic distance between the C. bullosum clade and the lineage formed by Arhythmorhynchus brevis, Polymorphus sp., and Southwellina hispida is 23%. The average genetic p -distances between the clades of C. bullosum and the outgroups, Plagiorhynchidae and Centrorhynchidae were 28% and 29%, respectively. Table 4 Species of acanthocephalans, their hosts, locations and GenBank accession number of the sequences used in the phylogenetic analysis. Species Host Location Genbank access References Andracantha gravida (Alegret, 1941) Schmidt, 1975 Phalacrocorax auritus Yucatán, México EU267822 [ 35 ] Andracantha leucocarboi Presswell, García-Varela & Smales, 2017 Leucocarbo chalconotus New Zealand MF527025 [ 18 ] Andracantha phalacrocoracis (Yamaguti, 1939) Zalophus californianus USA MK119254 [ 36 ] Andracantha sigma Presswell, García-Varela & Smales, 2017 Phalacrocorax punctatus New Zealand MF527035 [ 18 ] Andracantha sp. Osmerus dentex Hokkaido, Japan LC465333 [ 37 ] Andracantha sp. Hypomesus japonicus Hokkaido, Japan LC465391 [ 37 ] Arhytmorhynchus brevis Van Cleave, 1916 Nycticorax nycticorax DQ089717 [ 38 ] Arhytmorhynchus frassoni (Molin, 1858) Eudocimus albus Sinaloa, México JX442188 [ 29 ] Bolbosoma balaenae (Gmelin, 1790) Balaenoptera physalus Capri Island, Italy MZ047281 [ 26 ] Bolbosoma caenoforme (Heitz, 1920) Salvelinus malma Taui Gulf, Asia KF156891 [ 39 ] Bolbosoma turbinella (Diesing, 1851) Paralichthys isosceles Rio de Janeiro, Brazil KU314823 Not published Bolbosoma sp. Homo sapiens Japan LC377776 [ 40 ] Bolbosoma sp. Callorhinus ursinus Alaska, USA JX442190 [ 29 ] Corynosoma bullosum Mirouga leonina King George Island, Antarctic Peninsula This study Corynosoma bullosum Mirounga leonina King George Island, Antarctic Peninsula This study Corynosoma australe Johnston, 1937 Stenella clymene Argentina MW724483 [ 41 ] Corynosoma enhydri Morozov, 1940 Enhydra lutris DQ089719 [ 38 ] Corynosoma hannae Zdzitowiecki, 1984 Colistium guntheri Otago, New Zealand KY909263 [ 42 ] Corynosoma magdaleni Montreuil, 1958 Phoca vitulina North, Baltic Sea, Germany MF078642 Not published Corynosoma nortmeri Waindoka, Lehnert, Siebert, Pawliczka & Strube, 2018 Phoca vitulina North, Baltic Sea, Germany MF001278 [ 43 ] Corynosoma obtuscens Lincicome, 1943 Callorhinus ursinus Alaska, USA JX442192 [ 29 ] Corynosoma semerme (Forssell, 1904) Luhe, 1911 Phoca largha Hokkaido, Japan LC465313 [ 37 ] Corynosoma strumosum (Rudolphi, 1802) Luhe, 1904 Neophocaena phocanoides Hokkaido, Japan LC465402 [ 37 ] Corynosoma validum Van Cleave, 1953 Callorhinus ursinus USA MK119252 [ 36 ] Hexaglandula corynosoma (Travassos, 1915) Nyctanassa violacea Mexico EU189488 Not published Ibirhynchus dimorpha (Schmidt, 1973) Eudocimus albus Gulf of Mexico GQ981438 [ 44 ] Polymorphus magnus Skrjabin, 1913 Larus schistisagus Russia OL689013 Not published Polymorphus minutus (Zeder, 1800) Luhe, 1911 Gammarus pulex Dijon, France EF467865 [ 27 ] Polymorphus obtusus Van Cleave, 1918 Aythya affinis California, Mexico JX442195 [ 29 ] Polymorphus phippsi Kostylev, 1922 Gammarus setosus Russia OL676687 Not published Polymorphus trochus Van Cleave, 1945 Fulica americana Sinaloa, Mexico JX442196 [ 29 ] Polymorphus sp. Anas platyrhynchos Austria MT184813 Not Published Polymorphus sp. Oligosarcus jenynsii Arroyo Grande, Argentina MT580125 [ 45 ] Profilicollis altmani (Perry, 1942) Leucophaeus modestus Valdivia, Chile KX702245 [ 21 ] Profilicollis botulus (Van Cleave, 1916) Carcinus maenas Wadden Sea, Netherlands KX279935 [ 46 ] Profilicollis chasmagnathi (Holcman-Spector, Mane-Garzon & Dei-Cas, 1978) Larus dominicanus Península Valdés, Argentina MG859266 [ 47 ] Profilicollis novaezelandensis Brockerhoff & Smales, 2002 Hemigrapsus crenulatus New Zealand MG602475 [ 48 ] Pseudocorynosoma anatarium (Van Cleave, 1945) Aznar, Perez-Ponce de Leon & Raga, 2006 Bucephala albeola Mexico KX688148 [ 49 ] Pseudocorynosoma constrictum (Van Cleave, 1918) Aznar, Perez-Ponce de Leon & Raga, 2006 Anas diazi Mexico KX688132 [ 49 ] Pseudocorynosoma tepehuanesi García-Varela, Hernández-Orts & Pinacho-Pinacho, 2017 Oxyura jamaicensis Mexico KX688139 [ 49 ] Southwelina hispida (Van Cleave, 1925) Egretta garzetta Tabasco, Mexico EF467868 [ 27 ] Tenuisoma tarapungi Presswell, Bennett & Smales, 2020 Chroicocephalus novaehollandiae New Zealand MN688202 [ 19 ] Centrorhynchus globocaudatus (Zeder, 1800) Buteo buteo Italy MT992255 [ 50 ] Sphaeristrosis lanceoides (Petrochenko, 1949) Bufo gargarizans Cantor Yuyao, China MG931942 [ 51 ] Plagiorhynchus cylindraceus Atelerix algirus Balearic Islands, Spain MK300542 Not Published Discussion Our work provides a redescription of Corynosoma bullosum , including a comparison with existing measures and, for the first time, scanning electron microscope photographs and an assessment of its phylogenetic position based on COI DNA sequences. We considered that Zdzitowiecki et al. [ 1 , 6 ] provided valuable data on the morphology of C. bullosum , but that information is partial. On the other hand, molecular data presented by García-Varela [ 7 ] include ITS and 5.8s rRNA sequences, but unfortunately, they are not comparable to previous essays. The use of COI allowed us to assess the phylogenetic position of C. bullosum with other species of Corynosoma allowing at the same time to correlate morphology with molecular data. The host for C. bullosum is the southern elephant seal, Mirounga leonina. However, it has been parasitizing other marine species of birds and mammals, which are considered unsuitable hosts [ 1 , 5 , 14 ]. Besides C. bullosum , two other species of Corynosoma , C. australe [ 15 , 16 ] and C. cetaceum [ 17 ], have been found in southern elephant seals. However, we did not find any specimen of the latter species in our samples. Similarly, although it has been recorded mainly in Antarctic and sub-Antarctic regions, there are reports of immature specimens of C. bullosum in the sperm whale, in the north of Argentinean Patagonia [ 1 , 6 ]. In a pilot study with southern elephant seals in Patagonia, we have analysed some samples with negative results for species of Corynosoma (Soto, unpublished data). Available descriptions of C. bullosum differ among them presenting differences in some measures. The first description reported by Linstow 1892 mentions 25 rows of hooks with eight hooks per row. while the later posterior descriptions, including this study, report a mean of 16 rows of hooks with 12 hooks per row. However, total body dimensions of females and males described by Linstow fall within the range reported by later authors (Edmonds 1954, Zdzitowiecki 1986, present study). In the case of Edmonds [ 5 ], the author provides a more detailed list of measures; however, for most of the measurements the author did not differentiate between females and males in most of the measurements. Finally, the description of Zdzitowiecki [ 6 ] is the most comprehensive, and provided measurements agree with ours. Our molecular analysis showed that C. bullosum from southern elephant seals exhibits a low level of genetic variation. Recovered haplotypes differ on average by 0.7%. Also, haplotypes of this species are highly divergent from other members of the Polymorphidae family (20–26%). However, this species appears as sister species to Andracantha sigma , with a relatively low genetic divergence (10%). In the family Polymorphidae, low genetic diversity has been estimated within species of the genera Andracantha, Corynosoma, Profilicollis , and Tenuisoma [ 7 , 18 , 19 , 20 , 21 , 22 ]. The same is valid for members of Archiacanthocephala class [ 23 , 24 ]. Therefore, this seems to be a consistent pattern within the Acanthocephala group. In general, marine birds and mammals exhibit a high vagility. This behaviour contributes to the dispersal of parasites' eggs, resulting in a genetic homogenization of the population and, consequently, a low genetic diversity [ 18 , 20 , 25 , 26 ]. However, this may not be the only cause of the level of genetic diversity found. Even if the combination of molecular and morphological tools is considered a proper approach to resolve taxonomic ambiguities within acanthocephalans, not all species are considered valid, according to the sequences available in GenBank [ 26 ]. Many of them are from different mitochondrial genes, sometimes preventing comparisons [ 19 , 24 , 26 ]. Future studies should focus on adding other mitochondrial and more variable nuclear markers to clarify whether this observed pattern holds for different molecular markers. Our analyses show that phylogenetic relationships among the family Polymorphidae are not fully resolved. Most studies suggested that the classification of the Phylum Acanthocephala based only on morphological characters is unstable due to the conservative and simple morphology of the group [ 18 , 19 , 27 , 28 ]. For example, we found that the clades formed by the species belonging to the Andracantha and Corynosoma are poorly resolved. A similar situation occurs with the clades formed by the genera Polymorphus and Arhythmorhynchus . These findings are in agreement with previous phylogenetic analyses in members of the family the Polymorphidae provided by García-Varela et al. (2013) [ 29 ]; Presswell et al. [ 18 , 19 ], Santoro et al. [ 26 ]. Additional analyses, including robust taxonomic and character sampling, are much needed to obtain a robust phylogeny that supports a more stable classification. Especially for marine mammals parasites, which we know that they are hard to sample. We considered that other studies should tackle the relationships among species of the family Polymorphidae, which still are unstable, suggesting that the limits of the genera that formed this family need to be further evaluated. Finally, it is worth mentioning that in previous studies, samples were obtained by necrosis or shooting. In the present work, we got parasites from fecal samples. As was reported by Rengifo-Herrera et al. (2014) [ 30 ], we also found some helminth parasites. Remarkably, the studies on host-parasite association in Antarctic phocids are still poor and scarce. In some cases, descriptions are incomplete, outdated, and/or differ over years. Considering the increasing impact of climate change in Antarctica, long-term analyses are required to understand the effect on the host-parasite dynamic. As such, the sampling technique used here, may prove useful for geographically extensive and relatively fast parasite sampling. Conclusions We provided an updated morphological redescription for Corynosoma bullosum including electron microscopy photographs and molecular data. The COI gene sequences revealed that C. bullosum has low genetic variation and that this species is more closely related to Andracantha sigma than to the genus Corynosoma . Our results show that it is necessary to perform a phylogenetic study of the family Polymorphidae including all the species. Figure 1 . a. General view of Antarctica where specimens of the acanthocephalan Corynosoma bullosum were collected from feces of the southern elephant seal; b. Antarctic Specially Protected Area (ASPA) N° 132, in “Península Potter”, South Shetland islands, Antarctica. Figure 2 . Scanning electron microscopy (SEM) photographs of specimens of the acanthocephalan Corynosoma bullosum from the southern elephant seal. a. adult female; b. adult male; c. neck and proboscis detail; d. everted copulatory pouch; e. genital hooks surrounding the genital pore; f. apical hooks; g. basal hooks. Scale bars: a-b 1mm; c, d, e 100µm; f-g 20µm. Figure 3 . Genealogical relationships of haplotypes of the COI gene of specimens of the Polymorphidae family recovered in a Bayesian inference analysis. Numbers next to nodes refer to support values. Bayesian posterior probability values are shown left of the diagonal and Bootstrap proportions gathered in the Maximum Likelihood analysis (Ln = − 11155.091) are shown right of the diagonal. GenBank accession numbers are included in the terminal labels. Declarations Acknowledgements We thank Alex González for his assistance with the laboratory work in Sistemática Lab from Universidad Austral de Chile and to Dr. Guillermo D’Elía for his comments on the phylogenetic analysis; Mauricio Luquet (SEM unit, Aluminio Argentino) for help with SEM photographs; Martín Durante, Jorge Rossi and Maximiliano Perier whose involved in fieldwork assistance at Península Potter. The study was financially and logistically supported by the Dirección Nacional del Antártico, Instituto Antártico Argentino. The permit for this work was granted by the Dirección Nacional del Antártico (Environmental Office). Thanks are also given to the restored Ministerio de Ciencia, Tecnologı́a e Innovación Productiva de la Nación for the promotion of the scientific Argentinean program and the support to public education. We also want to express our heartfelt gratitude and appreciation to all the healthcare workers and researchers working in the frontline against the pandemic for COVID-19. FS, MSL, JN, and FC are members of CONICET. Ethics approval and consent to participate Not applicable. The whole study was non-invasive for the studied animals. Consent for publication Not applicable. Competing interests The authors declare that they have no competing interests. Authors’ contributions FAS, SMR, MSL, JN, and FC conceived the ideas and designed the methodology; FAS, MSL, and FC collected and processed the samples; FAS, SMR, and FC analysed the samples and data; FAS, SMR, MSL, and FC led the writing of the manuscript. All authors contributed critically to the drafts and gave final approval for publication. Funding This study was not granted. Availability of data and materials The datasets used and/or analysed during the current study are available on OSFHOME: https://osf.io/bzhq5/?view_only=c7049f30be6b420eb6c38fe91a138543 . The entire DNA sequences of this Acanthocephala will be released on October 17, 2022. Some SEM photographs generated during this study are included in this published article. References Laskowski Z, Zdzitowiecki K. Acanthocephalans in Sub-Antarctic and Antarctic. In Biodiversity and evolution of parasitic life in the Southern Ocean. Springer, Cham. 2017;p.141–182. Hernández-Orts JS, Smales LR, Pinacho-Pinacho CD, García-Varela M, Presswell B. Novel morphological and molecular data for Corynosoma hannae Zdzitowiecki, 1984 (Acanthocephala: Polymorphidae) from teleosts, fish-eating birds and pinnipeds from New Zealand. Parasitol. Int. 2017;66(1):905–916. Linstow O. Helminthen von Stidgeorgien. Nach der Ausbeute der deutschen Station von 1882–1883. Jb Hamb Wiss Anst. 1892;9:59–77. Johnston TH, Edmonds S. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-1879398","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":127377239,"identity":"e817aa26-bea6-4b02-86b3-2e59954f6caf","order_by":0,"name":"Florencia A. 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Leonardi","email":"","orcid":"","institution":"CCT CONICET-CENPAT","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"María","middleName":"S.","lastName":"Leonardi","suffix":""},{"id":127377242,"identity":"0e187263-ba97-454e-937e-7ba0a2dce8ea","order_by":3,"name":"Javier Negrete","email":"","orcid":"","institution":"Instituto Antártico Argentino","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Javier","middleName":"","lastName":"Negrete","suffix":""},{"id":127377243,"identity":"fbe9d1de-3245-4daf-88d3-58ddc56a65f0","order_by":4,"name":"Florencia Cremonte","email":"","orcid":"","institution":"CCT CONICET-CENPAT","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Florencia","middleName":"","lastName":"Cremonte","suffix":""}],"badges":[],"createdAt":"2022-07-20 20:59:09","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-1879398/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-1879398/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":25050403,"identity":"da9b3f55-b148-459b-843b-72d6aae21398","added_by":"auto","created_at":"2022-08-10 16:23:07","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":215601,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003ea.\u003c/strong\u003e General view of Antarctica where specimens of the acanthocephalan \u003cem\u003eCorynosoma bullosum \u003c/em\u003ewere collected from feces of the southern elephant seal; \u003cstrong\u003eb.\u003c/strong\u003e Antarctic Specially Protected Area (ASPA) N° 132, in “Península Potter”, South Shetland islands, Antarctica.\u003c/p\u003e\u003cp\u003e\u003cbr\u003e\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-1879398/v1/61b215c829f6cede2ed645ce.png"},{"id":25050890,"identity":"213e6979-6640-4b53-8d2b-e5883c1331f2","added_by":"auto","created_at":"2022-08-10 16:28:07","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":497059,"visible":true,"origin":"","legend":"\u003cp\u003eScanning electron microscopy (SEM) photographs of specimens of the acanthocephalan \u003cem\u003eCorynosoma bullosum\u003c/em\u003e from the southern elephant seal. a. adult female; b. adult male; c. neck and proboscis detail; d. everted copulatory pouch; e. genital hooks surrounding the genital pore; f. apical hooks; g. basal hooks. Scale bars: a-b 1mm; c, d, e 100µm; f-g 20µm.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-1879398/v1/230351f0c5e2aed2cd34fd6a.png"},{"id":25050404,"identity":"5ba20056-5022-49da-a3dd-773a95c30fd9","added_by":"auto","created_at":"2022-08-10 16:23:08","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":125935,"visible":true,"origin":"","legend":"\u003cp\u003eGenealogical relationships of haplotypes of the COI gene of specimens of the Polymorphidae family recovered in a Bayesian inference analysis. Numbers next to nodes refer to support values. Bayesian posterior probability values are shown left of the diagonal and Bootstrap proportions gathered in the Maximum Likelihood analysis (Ln = –11155.091) are shown right of the diagonal. GenBank accession numbers are included in the terminal labels.\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-1879398/v1/699869de191a0840254e1e30.png"},{"id":25298495,"identity":"c055038b-abf6-4931-97c3-c1f5762a7ae4","added_by":"auto","created_at":"2022-08-17 05:14:14","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1175283,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-1879398/v1/1ffa12ab-b8e6-4b12-9d53-aaa381448654.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Morphological and molecular updates of Corynosoma bullosum (Linstow, 1892) Raulliet \u0026 Henry, 1907 parasitizing southern elephant seals from the Antarctic Peninsula","fulltext":[{"header":"Background","content":"\u003cp\u003eThe acanthocephalan genus \u003cem\u003eCorynosoma\u003c/em\u003e includes species from the gastrointestinal tract of pinnipeds [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e], thirteen of which parasitize seals and fur seals worldwide [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Some of these species have been described in Antarctic and sub-Antarctic pinnipeds, e.g. \u003cem\u003eC. hamanni\u003c/em\u003e (Linstow, 1892), \u003cem\u003eC. bullosum\u003c/em\u003e (Linstow, 1892), \u003cem\u003eC. australe\u003c/em\u003e Johnston, 1937, \u003cem\u003eC. arctocephali\u003c/em\u003e Zdzitowiecki, 1984, \u003cem\u003eC. hannae\u003c/em\u003e Zdzitowiecki, 1984, \u003cem\u003eC. pseudohamanni\u003c/em\u003e Zdzitowiecki, 1984, \u003cem\u003eC. evae\u003c/em\u003e Zdzitowiecki, 1984 and \u003cem\u003eC. gibsoni\u003c/em\u003e Zdzitowiecki, 1986 (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Particularly, the southern elephant seal, \u003cem\u003eMirounga leonina\u003c/em\u003e, has been reported as the only suitable definitive host for \u003cem\u003eC. bullosum\u003c/em\u003e. A questionable record indicates the northern elephant seal, \u003cem\u003eM. angustrirostris\u003c/em\u003e, as another suitable definitive host [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. In addition, larval stages of \u003cem\u003eC. bullosum\u003c/em\u003e were found in the sperm whale, probably as an unsuitable definitive host [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Larval specimens were also found in the intestine of seabirds, such as the cormorant and the gentoo penguin [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eDifferent \u003cem\u003eCorynosoma\u003c/em\u003e species described in Antarctic and sub-Antarctic pinnipeds; * Unsuitable definite host, (?) Questionable report.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eCorynosoma\u003c/em\u003e species\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eHost\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eLocality\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eReference\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cspan type=\"BoldItalic\" class=\"BoldItalic\" name=\"Emphasis\"\u003eC. hamanni\u003c/span\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eHydrurga leptonyx\u003c/em\u003e\u003c/p\u003e \u003cp\u003e\u003cem\u003eLeptonychotes weddelli\u003c/em\u003e\u003c/p\u003e \u003cp\u003e\u003cem\u003eLobodon carcinophaga*\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eSouth Shetlands\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cspan type=\"BoldItalic\" class=\"BoldItalic\" name=\"Emphasis\"\u003eC. bullosum\u003c/span\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eMirounga leonina\u003c/em\u003e\u003c/p\u003e \u003cp\u003e\u003cem\u003eMirounga angustirostris\u003c/em\u003e (?)\u003c/p\u003e \u003cp\u003e\u003cem\u003eHydrurga leptonyx*\u003c/em\u003e\u003c/p\u003e \u003cp\u003e\u003cem\u003eLeptonychotes weddelli*\u003c/em\u003e,\u003c/p\u003e \u003cp\u003e\u003cem\u003eLobodon carcinophaga*\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eSouth Shetlands\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cspan type=\"BoldItalic\" class=\"BoldItalic\" name=\"Emphasis\"\u003eC. australe\u003c/span\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eHydrurga leptonyx\u003c/em\u003e\u003c/p\u003e \u003cp\u003e\u003cem\u003eOtaria flavescens\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eSouth Shetlands\u003c/p\u003e \u003cp\u003ePatagonia Argentina\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e, \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e, \u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cspan type=\"BoldItalic\" class=\"BoldItalic\" name=\"Emphasis\"\u003eC. arctocephali\u003c/span\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eArctocephalus gazella\u003c/em\u003e\u003c/p\u003e \u003cp\u003e\u003cem\u003eHydrurga leptonyx\u003c/em\u003e\u003c/p\u003e \u003cp\u003e\u003cem\u003eLobodon carcinophaga*\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eSouth Shetland\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cspan type=\"BoldItalic\" class=\"BoldItalic\" name=\"Emphasis\"\u003eC. hannae\u003c/span\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eHydrurga leptonyx\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eSouth Shetland\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cspan type=\"BoldItalic\" class=\"BoldItalic\" name=\"Emphasis\"\u003eC. pseudohamani\u003c/span\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eLeptonychotes weddelli\u003c/em\u003e\u003c/p\u003e \u003cp\u003e\u003cem\u003eLobodon carcinophaga\u003c/em\u003e\u003c/p\u003e \u003cp\u003e\u003cem\u003eHydrurga leptonyx*\u003c/em\u003e\u003c/p\u003e \u003cp\u003e\u003cem\u003eMirounga leonina*\u003c/em\u003e\u003c/p\u003e \u003cp\u003e\u003cem\u003eArctocephalus gazella*\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eSouth Shetlands\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cspan type=\"BoldItalic\" class=\"BoldItalic\" name=\"Emphasis\"\u003eC. evae\u003c/span\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eHydrurga leptonyx\u003c/em\u003e\u003c/p\u003e \u003cp\u003e\u003cem\u003eOtaria flavescens\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eSouth Shetlands\u003c/p\u003e \u003cp\u003ePatagonia Argentina\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cspan type=\"BoldItalic\" class=\"BoldItalic\" name=\"Emphasis\"\u003eC. gibsoni\u003c/span\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eOtaria flavescens\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMalvinas Islands\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eThe acanthocephalan \u003cem\u003eC. bullosum\u003c/em\u003e was first described by Linstow in 1892 [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]; from elephant seals in South Georgia. Since this first description, several later findings and reports have been mentioned below. The different available descriptions for the species present several discrepancies in the measurements, principally in total body length, the number of rows of hooks, and the number of hooks per row [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. The report by Johnston \u0026amp; Edmonds 1953 [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e] briefly described the species based on a single female specimen found in the intestine of an elephant seal on the Campbell and Auckland Islands. On an Antarctic expedition in 1949, Edmonds et al. (1954) [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e] obtained several acanthocephalans in the Heard Islands that allowed them to give several measurements. Later, in a morphological description carried out by Zdzitowiecki 1986 [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e] measurements of 20 females and 20 males were given, which were recovered from the intestine of three elephant seals from the South Shetland Islands.\u003c/p\u003e \u003cp\u003eAt present, the contribution of Laskowski and Zdzitowiecki (2017) [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e] constitutes the complete study of the morphology of \u003cem\u003eCorynosoma\u003c/em\u003e species from Antarctica and the sub-Antarctic region. They also provide a list of suitable and unsuitable definitive hosts, as well as paratenic and intermediate hosts. On the other hand, phylogenetic analysis of the genera \u003cem\u003eCorynosoma\u003c/em\u003e based on ITS and 5.8s rRNA sequences supported the monophyly of the family and some of their genera [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. However, considering the discrepancies in the morphological descriptions and the absence of a correlation between molecular and morphological data, this work provides a morphological and molecular update of \u003cem\u003eC. bullosum.\u003c/em\u003e\u003c/p\u003e"},{"header":"Materials And Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eSpecimens collection\u003c/h2\u003e \u003cp\u003eDuring the reproductive seasons of 2016/2017 and 2017/2018, 29 specimens of acanthocephalans were collected from fecal samples from 41 southern elephant seals, \u003cem\u003eMirounga leonina\u003c/em\u003e Linnaeus, 1758 (Pinnipedia, Phocidae). The fieldwork was conducted in the Antarctic Specially Protected Area ASPA N\u0026deg;132, \u0026ldquo;Pen\u0026iacute;nsula Potter\u0026rdquo;, near the Argentinean Scientific Base \u0026ldquo;Dr. Alejandro Carlini\u0026rdquo;, 25 de Mayo/King George Island (62\u0026deg;14\u0026rsquo;S 51 58\u0026deg;40\u0026rsquo;W) (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Fecal samples were obtained directly from the ground, very close to the animals. To avoid contamination, we collected only the top of the feces. Animals showed no signs of illness at the time of collection and all feces samples were fresh. The samples were frozen at -20\u0026deg;C and then examined under a stereomicroscope. Parasites were collected, placed in distilled water, and repeatedly washed; subsequently, they were individually preserved in 96% ethanol. We also checked fecal samples from eight Weddell seals (\u003cem\u003eLeptonychotes weddellii\u003c/em\u003e) and one crabeater seal (\u003cem\u003eLobodon carcinophaga\u003c/em\u003e) but we did not find any acanthocephalan.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003eMorphological study\u003c/h2\u003e \u003cp\u003eSome selected specimens (10 females and 10 males in good condition) were cleared in lactic acid and studied under a light microscope (Leica DM 2500) for morphological description. Measurements were taken using the Leica Application Suite microscope software. For scanning electron microscopy (SEM), a female and a male were gradually dehydrated in an ethanol series, immersed in hexamethyldisilazane for 15 min, and air-dried for 10 min. Photomicrographs of a female and a male were obtained with a Jeol JSM-6460LV SEM operating at 15 kV (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). All the measurements are in millimetres unless otherwise stated (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). The number of hooks per row was determined in all the specimens by counting in 4 neighbouring rows, following Zdzitowiecki (1986). Vouchers were deposited at the Parasitological Collection of the Instituto de Biolog\u0026iacute;a de Organismos Marinos, Puerto Madryn, Chubut province, Argentina (CNP-Par 197 and CNP-Par 198).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eComparative measurements of \u003cem\u003eCorynosoma bullosum\u003c/em\u003e from southern elephant seal; measures in millimetres mean and range in parenthesis. *The author did not differ by sex.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eReference\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eLinstow (1892)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eEdmonds (1954)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eZdzitowiecki (1986)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003ePresent study\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eHost\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cem\u003eMirounga leonina\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003eMirounga leonina\u003c/em\u003e\u003c/p\u003e \u003cp\u003e\u003cem\u003eHydrurga leptonyx\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cem\u003eMirounga leonina\u003c/em\u003e\u003c/p\u003e \u003cp\u003e\u003cem\u003eLobodon carcinophaga\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cem\u003eMirounga leonina\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLocality\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eSouth Georgia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eHeard and Macquarie Islands\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eSouth Shetlands\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003ePotter Cove\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003en\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eNot specific\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"3\" rowspan=\"4\"\u003e \u003cp\u003eGeneral\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNumber of rows of hooks\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e15\u0026ndash;16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e16\u0026ndash;18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e16\u0026ndash;18\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNumber of hooks per row\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e11\u0026ndash;13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e10\u0026ndash;15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e11\u0026ndash;15\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNumber apical hooks per row\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e8\u0026ndash;9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e7\u0026ndash;11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e8\u0026ndash;12\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNumber basal hooks per row\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3\u0026ndash;4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2\u0026ndash;4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e3\u0026ndash;4\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"10\" rowspan=\"11\"\u003e \u003cp\u003eFemale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eBody length\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e13.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e13.6\u0026ndash;19.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e17.1(13.7\u0026ndash;20.0)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eTrunk dimensions\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e12.01-17.8x1.8-2.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e12.7-18.1x2.0-2.9\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eProboscis length\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.94\u0026ndash;1.10*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.11\u0026ndash;1.33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1.21(1.15\u0026ndash;1.27)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eProboscis width\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.26*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.34\u0026ndash;0.40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.39(0.32\u0026ndash;0.45)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eProboscis receptacle (length to width)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.4x0.30*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.87-2.27x0.37-0.55\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1.75-1.82-x0.43-0.55\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLargest hook\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.087*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.099-0120\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.11(0.093\u0026ndash;0.123)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNeck dimensions (length to width)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.4 length*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.45\u0026ndash;0.62 length\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.43x0.55\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLemnisci\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.13-1.70x0.70-1.25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1.03-1.50x0.59-1.12\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eGenital complex (length)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3.5 length\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2.5\u0026ndash;3.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e3.1(2.6\u0026ndash;3.2)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eGenital spines\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3-120\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e5-115\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eEggs (length to width)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.13x0.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.10x0.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.107-0.125x0.035-0.039\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.112-0.123x0.033-0.035\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"11\" rowspan=\"12\"\u003e \u003cp\u003eMale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eBody length\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e7.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e9.6\u0026ndash;13.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e12.8(9.5\u0026ndash;13.6)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eTrunk dimensions\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.97\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e8.0-11.7x1.4-2.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e7.9-11.3x1.3-1.9\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eProboscis length\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.94\u0026ndash;1.10*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.91\u0026ndash;1.35\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1.11(0.90\u0026ndash;1.15)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eProboscis width\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.26*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.31\u0026ndash;0.37\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.29(0.28\u0026ndash;0.33)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eProboscis receptacle (length to width)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.4x0.30*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.63-2.22x0.27-0.51\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1.36-1.66x0.25-0.45\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLargest hook\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.087*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.089-0117\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.109(0.093\u0026ndash;0.123)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNeck dimensions (length to width)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.4 length*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.37\u0026ndash;0.48 length\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.33x0.43\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLemnisci\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.85-1.54x0.57-0.90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.80-1.40x0.47-0.77\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRight testis (length to width)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.7-0.9x0.32-0.45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.78-1.51x0.32-0.71\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.73-1.33x0.35-0.50\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLeft testis (length to width)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.68-1.62x0.41-0.69\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.70-1.53x0.37-0.55\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eGenital spines\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e80\u0026ndash;250\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e90\u0026ndash;230\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCements glands\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eEvert copulatory pouch\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.08x0.99\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.94x0.83\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eMolecular study\u003c/h2\u003e \u003cp\u003eGenetic comparison and phylogenetic analyses were based on a fragment of 631 bp of the mitochondrial cytochrome oxidase I (COI) gene. Sequences of two individuals of \u003cem\u003eCoryonsoma bullosum\u003c/em\u003e from the southern elephant seal, \u003cem\u003eMirounga leonina\u003c/em\u003e, from Pen\u0026iacute;nsula Potter, Antarctic Peninsula, were analysed. The samples were digested overnight at 55\u0026deg;C and genomic DNA was isolated using a commercial extraction kit (Wizard\u0026reg; Genomic DNA Purification Kit, Promega, Madison, WI, USA). A fragment of the COI gene was amplified using the primers detailed by Folmer et al. [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e] following the protocol of Amin et al. (2019) [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. Amplicons were sequenced using an external sequencing service (Macrogen, Inc., Seoul, South Korea). The new DNA sequences were edited using Codon-Code (Codon Code Aligner, Dedham, Massachusetts) and deposited in GenBank (OP142751-OP142752).\u003c/p\u003e \u003cp\u003eThe new COI sequence was integrated into a matrix with one representative of each genus of the family Polymorphidae. A total of 42 belonging to the family Polymorphidae were downloaded from GenBank (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e4\u003c/span\u003e) and analysed. In addition, we used as outgroup the phylogenetically related species \u003cem\u003ePlagiorhynchus cylindraceus\u003c/em\u003e and \u003cem\u003eCentrorhynchus globocaudatis\u003c/em\u003e (Plagiorhynchidae), and \u003cem\u003eSphaerirostris lanceoides\u003c/em\u003e (Centrorhynchidae). As such, the analysed matrix has a total of 45 sequences.\u003c/p\u003e \u003cp\u003eSequence alignment was done in Clustal as implemented in MEGA 7 [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e] using the default parameter values. Observed genetic distance (\u003cem\u003ep\u003c/em\u003e) between haplotypes and sample pairs were calculated in MEGA 7. jModelTest was used to select the model of nucleotide substitution (GTR\u0026thinsp;+\u0026thinsp;G\u0026thinsp;+\u0026thinsp;I). Two methods of phylogenetic inference were implemented, Maximum Likelihood (ML) and Bayesian inference (BI). The ML analysis was conducted with IQ-TREE using the online implementation W-IQ-TREE (\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps:/iqtree.cibiv.univie.ac.at\u003c/span\u003e\u003cspan address=\"https://iqtree.cibiv.univie.ac.at\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e; [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]), with perturbation strength set to 0.5 and stopping rule set to 100. Clade support was calculated with 1,000 ultrafast bootstrap pseudo-replications (BS). The BI analysis was conducted with MrBayes 3.1 [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e] with two independent runs with four heated and one cold Markov chain each. Runs lasted 20\u0026nbsp;million generations and parameters and trees were sampled every 1,000 generations. Model parameters were estimated in MrBayes. Convergence to stable log-likelihood values was checked by plotting log-likelihood values against generation time. The first 25% of the tree sampled were discarded as burn-in; the remaining trees, all from the convergence zone, were used to compute 50% majority rule consensus trees and to obtain posterior probability (PP) values for each clade.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eIn Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e, we summarise the comparative measurements of females and males of the acanthocephalan \u003cem\u003eCorynosoma bullosum\u003c/em\u003e from the southern elephant seal, given by the different authors and the present data.\u003c/p\u003e \u003cp\u003e \u003cem\u003eMorphological data of\u003c/em\u003e Corynosoma bullosum \u003cem\u003e(Linstow, 1892)\u003c/em\u003e\u003c/p\u003e \u003cp\u003eThe presence of 16\u0026ndash;18 rows of hooks with 11\u0026ndash;15 hooks each one (8\u0026ndash;12 anterior and 3\u0026ndash;4 basal hooks some rootless) are the diagnosis characteristics for \u003cem\u003eC. bullosum\u003c/em\u003e. Specimens are white, great size, and with evident sexual dimorphism. Females are larger than males. Hind-trunk cylindrical, longer than fore-trunk. The trunk expands anteriorly forming a disc; spines spread ventrally. Genital spines surround the genital pore in both sexes. Lemnisci are flat and equal in size, shorter than proboscis receptacle. Hooks' measurements are given in Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e3\u003c/span\u003e. Females: Fore-trunk constitutes 20\u0026ndash;30% of trunk length. Somatic armature covers 30\u0026ndash;40% of trunk length on the ventral side. Genital pore terminal. Males: Fore-trunk constitutes 25\u0026ndash;35% of trunk length. Somatic armature covers 35\u0026ndash;50% of trunk length on the ventral side.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eDimensions of proboscis hooks of \u003cem\u003eCorynosoma bullosum\u003c/em\u003e from southern elephant seal based on four neighboring rows of hooks in 10 females and 10 males; measures in millimetres mean and range in parenthesis.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"7\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eHook N\u0026deg;\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c4\" namest=\"c2\"\u003e \u003cp\u003eFemale\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c7\" namest=\"c5\"\u003e \u003cp\u003eMale\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003eThorn length\u003c/b\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003eBasal width\u003c/b\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003eRoot length\u003c/b\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003eThorn length\u003c/b\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cb\u003eBasal width\u003c/b\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u003cb\u003eRoot length\u003c/b\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eApical 1\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.108(0.093\u0026ndash;0.123)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.029(0.027\u0026ndash;0.032)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.094(0.091\u0026ndash;0.097)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.074(0.065\u0026ndash;0.08)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.022(0.019\u0026ndash;0.025)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0,064(0.061\u0026ndash;0.067)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eApical 2\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.092(0.087\u0026ndash;0.099)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.027(0.023\u0026ndash;0.030)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.077(0.075\u0026ndash;0.079)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.059(0.057\u0026ndash;0.063)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0,021(0.017\u0026ndash;0.027)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.059(0.057\u0026ndash;0.061)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eApical 3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.088(0.084\u0026ndash;0.098)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.025(0.022\u0026ndash;0.029)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.076(0.074\u0026ndash;0.078)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.060(0.058\u0026ndash;0.062)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.022(0.018\u0026ndash;0.026)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.059(0.058\u0026ndash;0.061)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eApical 4\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.089(0.084\u0026ndash;0.094)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.026(0.024\u0026ndash;0.029)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.072(0.071\u0026ndash;0.074)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.059(0.057\u0026ndash;0.062)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.021(0.018\u0026ndash;0.025)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.058(0.056\u0026ndash;0.060)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eApical 5\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.086(0.081\u0026ndash;0.091)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.029(0.026\u0026ndash;0.032)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.072(0.070\u0026ndash;0.075)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.059(0.056\u0026ndash;0.063)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.022(0.016\u0026ndash;0.026)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.057(0.055\u0026ndash;0.059)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eApical 6\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.083(0.081\u0026ndash;0.085)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.029(0.025\u0026ndash;0.032)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.073(0.071\u0026ndash;0.074)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.059(0.056\u0026ndash;0.062)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.020(0.017\u0026ndash;0.024)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.056(0.054\u0026ndash;0.058)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eApical 7\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.082(0.081\u0026ndash;0.084)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.031(0.028\u0026ndash;0.033)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.075(0.073\u0026ndash;0.077)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.058(0.055\u0026ndash;0.062)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.021(0.018\u0026ndash;0.023)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.055(0.053\u0026ndash;0.057)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eApical 8\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.081(0.078\u0026ndash;0.083)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.030(0.028\u0026ndash;0.032)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.079(0.075\u0026ndash;0.082)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.057(0.054\u0026ndash;0.060)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.019(0.017\u0026ndash;0.022)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.053(0.051\u0026ndash;0.056)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eApical 9\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.079(0.078\u0026ndash;0.080)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.030(0.027\u0026ndash;0.033)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.080(0.078\u0026ndash;0.083)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.055(0.052\u0026ndash;0.058)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.019(0.017\u0026ndash;0.021)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.052(0.049\u0026ndash;0.055)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eBasal 1\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.065(0.064\u0026ndash;0.066)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.020(0.018\u0026ndash;0.021)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.045(0.042\u0026ndash;0.049)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.039(0.037\u0026ndash;0.040)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eBasal 2\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.065(0.061\u0026ndash;0.069)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.016(0.013\u0026ndash;0.019)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.046(0.045\u0026ndash;0.048)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.039(0.037\u0026ndash;0.041)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eBasal 3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0,062(0.060\u0026ndash;0.063)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.014(0.013\u0026ndash;0.015)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.046(0.045\u0026ndash;0.047)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.039(0.037\u0026ndash;0.040)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003eMolecular results\u003c/h2\u003e \u003cp\u003eBoth phylogenetic trees gathered via ML and BI were mostly congruent (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). The Polymorphidae family was found to be monophyletic and with high support (PP\u0026thinsp;=\u0026thinsp;0.99; BS\u0026thinsp;=\u0026thinsp;69). Within the Polymorphidae clade, three lineages were found. One of these is the highly supported clade (PP\u0026thinsp;=\u0026thinsp;1; BS\u0026thinsp;=\u0026thinsp;97) formed by the genera \u003cem\u003eAndracantha, Bolbosoma\u003c/em\u003e, and \u003cem\u003eCorynosoma\u003c/em\u003e, where \u003cem\u003eBolbosoma\u003c/em\u003e is the single genus found in monophyletic (PP\u0026thinsp;=\u0026thinsp;1; BS\u0026thinsp;=\u0026thinsp;99). The genus \u003cem\u003eBolbosoma\u003c/em\u003e is sister to a clade (PP\u0026thinsp;=\u0026thinsp;0.81; BS\u0026thinsp;=\u0026thinsp;77) formed by all the species of \u003cem\u003eCorynosoma\u003c/em\u003e (PP\u0026thinsp;=\u0026thinsp;0.99; BS\u0026thinsp;=\u0026thinsp;89) except \u003cem\u003eCorynosoma bullosum\u003c/em\u003e, which is sister (PP\u0026thinsp;=\u0026thinsp;1; BS\u0026thinsp;=\u0026thinsp;100) to \u003cem\u003eAndracantha sigma\u003c/em\u003e and not to \u003cem\u003eCorynosoma\u003c/em\u003e clade (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). The other lineage is formed by \u003cem\u003ePolymorphus, Arhytmorhynchus, Profilicollis, Pseudocorynosoma, Tenuisoma, Hexaglandula\u003c/em\u003e, and \u003cem\u003eIbirhynchus\u003c/em\u003e genera, which appears well supported only in the BI analysis (PP\u0026thinsp;=\u0026thinsp;0.81; BS\u0026thinsp;=\u0026thinsp;48). The third lineage is formed by \u003cem\u003eArhytmorhynchus, Polymorphus\u003c/em\u003e, and \u003cem\u003eSouthwellina\u003c/em\u003e, which form a high supported clade (PP\u0026thinsp;=\u0026thinsp;1; BS\u0026thinsp;=\u0026thinsp;99; Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe genealogical analysis showed that our sequences from the southern elephant seal, fall in the \u003cem\u003eC. bullosum\u003c/em\u003e clade (PP\u0026thinsp;=\u0026thinsp;1; BS\u0026thinsp;=\u0026thinsp;100; Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). Haplotypes of \u003cem\u003eC. bullosum\u003c/em\u003e show extremely low genetic variation (0.7%). Both haplotypes differ from \u003cem\u003eA. sigma\u003c/em\u003e by 10%. Sequences of \u003cem\u003eC. bullosum\u003c/em\u003e with clades formed by \u003cem\u003eAndracantha\u003c/em\u003e and \u003cem\u003eBolbosoma\u003c/em\u003e members differ on average by 19%. Compared with the clade formed by \u003cem\u003eCorynosoma\u003c/em\u003e members, sequences of \u003cem\u003eC. bullosum\u003c/em\u003e differ by 21%. The average genetic \u003cem\u003ep\u003c/em\u003e-distances between the clade of \u003cem\u003eC. bullosum\u003c/em\u003e and the lineage formed by the genera \u003cem\u003eArhythmorhynchus, Polymorphus, Profilicollis, Pseudocorynosoma, Tenuisoma, Hexaglandula\u003c/em\u003e, and \u003cem\u003eIbirhynchus\u003c/em\u003e differ by 25%, and the genetic distance between the \u003cem\u003eC. bullosum\u003c/em\u003e clade and the lineage formed by \u003cem\u003eArhythmorhynchus brevis, Polymorphus\u003c/em\u003e sp., and \u003cem\u003eSouthwellina hispida\u003c/em\u003e is 23%. The average genetic \u003cem\u003ep\u003c/em\u003e-distances between the clades of \u003cem\u003eC. bullosum\u003c/em\u003e and the outgroups, Plagiorhynchidae and Centrorhynchidae were 28% and 29%, respectively.\u003c/p\u003e \u003c/div\u003e\n\u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eSpecies of acanthocephalans, their hosts, locations and GenBank accession number of the sequences used in the phylogenetic analysis.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSpecies\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eHost\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eLocation\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eGenbank access\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eReferences\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eAndracantha gravida\u003c/em\u003e (Alegret, 1941) Schmidt, 1975\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003ePhalacrocorax auritus\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eYucat\u0026aacute;n, M\u0026eacute;xico\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eEU267822\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eAndracantha leucocarboi\u003c/em\u003e Presswell, Garc\u0026iacute;a-Varela \u0026amp; Smales, 2017\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eLeucocarbo chalconotus\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eNew Zealand\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eMF527025\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eAndracantha phalacrocoracis\u003c/em\u003e (Yamaguti, 1939)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eZalophus californianus\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eUSA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eMK119254\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eAndracantha sigma\u003c/em\u003e Presswell, Garc\u0026iacute;a-Varela \u0026amp; Smales, 2017\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003ePhalacrocorax punctatus\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eNew Zealand\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eMF527035\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eAndracantha\u003c/em\u003e sp.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eOsmerus dentex\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eHokkaido, Japan\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eLC465333\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eAndracantha\u003c/em\u003e sp.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eHypomesus japonicus\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eHokkaido, Japan\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eLC465391\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eArhytmorhynchus brevis\u003c/em\u003e Van Cleave, 1916\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eNycticorax nycticorax\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eDQ089717\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eArhytmorhynchus frassoni\u003c/em\u003e (Molin, 1858)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eEudocimus albus\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eSinaloa, M\u0026eacute;xico\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eJX442188\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eBolbosoma balaenae\u003c/em\u003e (Gmelin, 1790)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eBalaenoptera physalus\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eCapri Island, Italy\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eMZ047281\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eBolbosoma caenoforme\u003c/em\u003e (Heitz, 1920)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eSalvelinus malma\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eTaui Gulf, Asia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eKF156891\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eBolbosoma turbinella\u003c/em\u003e (Diesing, 1851)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eParalichthys isosceles\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eRio de Janeiro, Brazil\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eKU314823\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eNot published\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eBolbosoma\u003c/em\u003e sp.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eHomo sapiens\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eJapan\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eLC377776\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eBolbosoma\u003c/em\u003e sp.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eCallorhinus ursinus\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eAlaska, USA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eJX442190\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eCorynosoma bullosum\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eMirouga leonina\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eKing George Island, Antarctic Peninsula\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003eThis study\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eCorynosoma bullosum\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eMirounga leonina\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eKing George Island, Antarctic Peninsula\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003eThis study\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eCorynosoma australe\u003c/em\u003e Johnston, 1937\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eStenella clymene\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eArgentina\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eMW724483\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eCorynosoma enhydri\u003c/em\u003e Morozov, 1940\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eEnhydra lutris\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eDQ089719\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eCorynosoma hannae\u003c/em\u003e Zdzitowiecki, 1984\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eColistium guntheri\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eOtago, New Zealand\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eKY909263\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eCorynosoma magdaleni\u003c/em\u003e Montreuil, 1958\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003ePhoca vitulina\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eNorth, Baltic Sea, Germany\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eMF078642\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eNot published\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eCorynosoma nortmeri\u003c/em\u003e Waindoka, Lehnert, Siebert, Pawliczka \u0026amp; Strube, 2018\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003ePhoca vitulina\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eNorth, Baltic Sea, Germany\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eMF001278\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eCorynosoma obtuscens\u003c/em\u003e Lincicome, 1943\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eCallorhinus ursinus\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eAlaska, USA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eJX442192\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eCorynosoma semerme\u003c/em\u003e (Forssell, 1904) Luhe, 1911\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003ePhoca largha\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eHokkaido, Japan\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eLC465313\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eCorynosoma strumosum\u003c/em\u003e (Rudolphi, 1802) Luhe, 1904\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eNeophocaena phocanoides\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eHokkaido, Japan\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eLC465402\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eCorynosoma validum\u003c/em\u003e Van Cleave, 1953\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eCallorhinus ursinus\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eUSA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eMK119252\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eHexaglandula corynosoma\u003c/em\u003e (Travassos, 1915)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eNyctanassa violacea\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMexico\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eEU189488\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eNot published\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eIbirhynchus dimorpha\u003c/em\u003e (Schmidt, 1973)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eEudocimus albus\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eGulf of Mexico\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eGQ981438\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e44\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003ePolymorphus magnus\u003c/em\u003e Skrjabin, 1913\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eLarus schistisagus\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eRussia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eOL689013\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eNot published\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003ePolymorphus minutus\u003c/em\u003e (Zeder, 1800) Luhe, 1911\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eGammarus pulex\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eDijon, France\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eEF467865\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003ePolymorphus obtusus\u003c/em\u003e Van Cleave, 1918\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eAythya affinis\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eCalifornia, Mexico\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eJX442195\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003ePolymorphus phippsi\u003c/em\u003e Kostylev, 1922\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eGammarus setosus\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eRussia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eOL676687\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eNot published\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003ePolymorphus trochus\u003c/em\u003e Van Cleave, 1945\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eFulica americana\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eSinaloa, Mexico\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eJX442196\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003ePolymorphus\u003c/em\u003e sp.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eAnas platyrhynchos\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eAustria\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eMT184813\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eNot Published\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003ePolymorphus\u003c/em\u003e sp.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eOligosarcus jenynsii\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eArroyo Grande, Argentina\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eMT580125\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eProfilicollis altmani\u003c/em\u003e (Perry, 1942)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eLeucophaeus modestus\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eValdivia, Chile\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eKX702245\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eProfilicollis botulus\u003c/em\u003e (Van Cleave, 1916)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eCarcinus maenas\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eWadden Sea, Netherlands\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eKX279935\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eProfilicollis chasmagnathi\u003c/em\u003e (Holcman-Spector, Mane-Garzon \u0026amp; Dei-Cas, 1978)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eLarus dominicanus\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePen\u0026iacute;nsula Vald\u0026eacute;s, Argentina\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eMG859266\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR47\" class=\"CitationRef\"\u003e47\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eProfilicollis novaezelandensis\u003c/em\u003e Brockerhoff \u0026amp; Smales, 2002\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eHemigrapsus crenulatus\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eNew Zealand\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eMG602475\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e48\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003ePseudocorynosoma anatarium\u003c/em\u003e (Van Cleave, 1945) Aznar, Perez-Ponce de Leon \u0026amp; Raga, 2006\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eBucephala albeola\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMexico\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eKX688148\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR49\" class=\"CitationRef\"\u003e49\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003ePseudocorynosoma constrictum\u003c/em\u003e (Van Cleave, 1918) Aznar, Perez-Ponce de Leon \u0026amp; Raga, 2006\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eAnas diazi\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMexico\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eKX688132\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR49\" class=\"CitationRef\"\u003e49\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003ePseudocorynosoma tepehuanesi\u003c/em\u003e Garc\u0026iacute;a-Varela, Hern\u0026aacute;ndez-Orts \u0026amp; Pinacho-Pinacho, 2017\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eOxyura jamaicensis\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMexico\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eKX688139\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR49\" class=\"CitationRef\"\u003e49\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eSouthwelina hispida\u003c/em\u003e (Van Cleave, 1925)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eEgretta garzetta\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eTabasco, Mexico\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eEF467868\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eTenuisoma tarapungi\u003c/em\u003e Presswell, Bennett \u0026amp; Smales, 2020\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eChroicocephalus novaehollandiae\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eNew Zealand\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eMN688202\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eCentrorhynchus globocaudatus\u003c/em\u003e (Zeder, 1800)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eButeo buteo\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eItaly\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eMT992255\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR50\" class=\"CitationRef\"\u003e50\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eSphaeristrosis lanceoides\u003c/em\u003e (Petrochenko, 1949)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eBufo gargarizans Cantor\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eYuyao, China\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eMG931942\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR51\" class=\"CitationRef\"\u003e51\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003ePlagiorhynchus cylindraceus\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eAtelerix algirus\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eBalearic Islands, Spain\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eMK300542\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eNot Published\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eOur work provides a redescription of \u003cem\u003eCorynosoma bullosum\u003c/em\u003e, including a comparison with existing measures and, for the first time, scanning electron microscope photographs and an assessment of its phylogenetic position based on COI DNA sequences. We considered that Zdzitowiecki et al. [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e] provided valuable data on the morphology of \u003cem\u003eC. bullosum\u003c/em\u003e, but that information is partial. On the other hand, molecular data presented by Garc\u0026iacute;a-Varela [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e] include ITS and 5.8s rRNA sequences, but unfortunately, they are not comparable to previous essays. The use of COI allowed us to assess the phylogenetic position of \u003cem\u003eC. bullosum\u003c/em\u003e with other species of \u003cem\u003eCorynosoma\u003c/em\u003e allowing at the same time to correlate morphology with molecular data.\u003c/p\u003e \u003cp\u003eThe host for \u003cem\u003eC. bullosum\u003c/em\u003e is the southern elephant seal, \u003cem\u003eMirounga leonina.\u003c/em\u003e However, it has been parasitizing other marine species of birds and mammals, which are considered unsuitable hosts [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. Besides \u003cem\u003eC. bullosum\u003c/em\u003e, two other species of \u003cem\u003eCorynosoma\u003c/em\u003e, \u003cem\u003eC. australe\u003c/em\u003e [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e] and \u003cem\u003eC. cetaceum\u003c/em\u003e [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e], have been found in southern elephant seals. However, we did not find any specimen of the latter species in our samples. Similarly, although it has been recorded mainly in Antarctic and sub-Antarctic regions, there are reports of immature specimens of \u003cem\u003eC. bullosum\u003c/em\u003e in the sperm whale, in the north of Argentinean Patagonia [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. In a pilot study with southern elephant seals in Patagonia, we have analysed some samples with negative results for species of \u003cem\u003eCorynosoma\u003c/em\u003e (Soto, unpublished data).\u003c/p\u003e \u003cp\u003eAvailable descriptions of \u003cem\u003eC. bullosum\u003c/em\u003e differ among them presenting differences in some measures. The first description reported by Linstow 1892 mentions 25 rows of hooks with eight hooks per row. while the later posterior descriptions, including this study, report a mean of 16 rows of hooks with 12 hooks per row. However, total body dimensions of females and males described by Linstow fall within the range reported by later authors (Edmonds 1954, Zdzitowiecki 1986, present study). In the case of Edmonds [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e], the author provides a more detailed list of measures; however, for most of the measurements the author did not differentiate between females and males in most of the measurements. Finally, the description of Zdzitowiecki [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e] is the most comprehensive, and provided measurements agree with ours.\u003c/p\u003e \u003cp\u003eOur molecular analysis showed that \u003cem\u003eC. bullosum\u003c/em\u003e from southern elephant seals exhibits a low level of genetic variation. Recovered haplotypes differ on average by 0.7%. Also, haplotypes of this species are highly divergent from other members of the Polymorphidae family (20\u0026ndash;26%). However, this species appears as sister species to \u003cem\u003eAndracantha sigma\u003c/em\u003e, with a relatively low genetic divergence (10%). In the family Polymorphidae, low genetic diversity has been estimated within species of the genera \u003cem\u003eAndracantha, Corynosoma, Profilicollis\u003c/em\u003e, and \u003cem\u003eTenuisoma\u003c/em\u003e [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. The same is valid for members of Archiacanthocephala class [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e, \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]. Therefore, this seems to be a consistent pattern within the Acanthocephala group. In general, marine birds and mammals exhibit a high vagility. This behaviour contributes to the dispersal of parasites' eggs, resulting in a genetic homogenization of the population and, consequently, a low genetic diversity [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e, \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e, \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eHowever, this may not be the only cause of the level of genetic diversity found. Even if the combination of molecular and morphological tools is considered a proper approach to resolve taxonomic ambiguities within acanthocephalans, not all species are considered valid, according to the sequences available in GenBank [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. Many of them are from different mitochondrial genes, sometimes preventing comparisons [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e, \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e, \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. Future studies should focus on adding other mitochondrial and more variable nuclear markers to clarify whether this observed pattern holds for different molecular markers.\u003c/p\u003e \u003cp\u003eOur analyses show that phylogenetic relationships among the family Polymorphidae are not fully resolved. Most studies suggested that the classification of the Phylum Acanthocephala based only on morphological characters is unstable due to the conservative and simple morphology of the group [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e, \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e, \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]. For example, we found that the clades formed by the species belonging to the \u003cem\u003eAndracantha\u003c/em\u003e and \u003cem\u003eCorynosoma\u003c/em\u003e are poorly resolved. A similar situation occurs with the clades formed by the genera \u003cem\u003ePolymorphus\u003c/em\u003e and \u003cem\u003eArhythmorhynchus\u003c/em\u003e. These findings are in agreement with previous phylogenetic analyses in members of the family the Polymorphidae provided by Garc\u0026iacute;a-Varela et al. (2013) [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]; Presswell et al. [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e], Santoro et al. [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. Additional analyses, including robust taxonomic and character sampling, are much needed to obtain a robust phylogeny that supports a more stable classification. Especially for marine mammals parasites, which we know that they are hard to sample. We considered that other studies should tackle the relationships among species of the family Polymorphidae, which still are unstable, suggesting that the limits of the genera that formed this family need to be further evaluated.\u003c/p\u003e \u003cp\u003eFinally, it is worth mentioning that in previous studies, samples were obtained by necrosis or shooting. In the present work, we got parasites from fecal samples. As was reported by Rengifo-Herrera et al. (2014) [\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e], we also found some helminth parasites. Remarkably, the studies on host-parasite association in Antarctic phocids are still poor and scarce. In some cases, descriptions are incomplete, outdated, and/or differ over years. Considering the increasing impact of climate change in Antarctica, long-term analyses are required to understand the effect on the host-parasite dynamic. As such, the sampling technique used here, may prove useful for geographically extensive and relatively fast parasite sampling.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eWe provided an updated morphological redescription for \u003cem\u003eCorynosoma bullosum\u003c/em\u003e including electron microscopy photographs and molecular data. The COI gene sequences revealed that \u003cem\u003eC. bullosum\u003c/em\u003e has low genetic variation and that this species is more closely related to \u003cem\u003eAndracantha sigma\u003c/em\u003e than to the genus \u003cem\u003eCorynosoma\u003c/em\u003e. Our results show that it is necessary to perform a phylogenetic study of the family Polymorphidae including all the species.\u003c/p\u003e \u003cp\u003eFigure \u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. \u003cb\u003ea.\u003c/b\u003e General view of Antarctica where specimens of the acanthocephalan \u003cem\u003eCorynosoma bullosum\u003c/em\u003e were collected from feces of the southern elephant seal; \u003cb\u003eb.\u003c/b\u003e Antarctic Specially Protected Area (ASPA) N\u0026deg; 132, in \u0026ldquo;Pen\u0026iacute;nsula Potter\u0026rdquo;, South Shetland islands, Antarctica.\u003c/p\u003e \u003cp\u003eFigure \u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. Scanning electron microscopy (SEM) photographs of specimens of the acanthocephalan \u003cem\u003eCorynosoma bullosum\u003c/em\u003e from the southern elephant seal. a. adult female; b. adult male; c. neck and proboscis detail; d. everted copulatory pouch; e. genital hooks surrounding the genital pore; f. apical hooks; g. basal hooks. Scale bars: a-b 1mm; c, d, e 100\u0026micro;m; f-g 20\u0026micro;m.\u003c/p\u003e \u003cp\u003eFigure \u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e. Genealogical relationships of haplotypes of the COI gene of specimens of the Polymorphidae family recovered in a Bayesian inference analysis. Numbers next to nodes refer to support values. Bayesian posterior probability values are shown left of the diagonal and Bootstrap proportions gathered in the Maximum Likelihood analysis (Ln = \u0026minus;\u0026thinsp;11155.091) are shown right of the diagonal. GenBank accession numbers are included in the terminal labels.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe thank Alex Gonz\u0026aacute;lez for his assistance with the laboratory work in Sistem\u0026aacute;tica Lab from Universidad Austral de Chile and to Dr. Guillermo D\u0026rsquo;El\u0026iacute;a for his comments on the phylogenetic analysis; Mauricio Luquet (SEM unit, Aluminio Argentino) for help with SEM photographs; Mart\u0026iacute;n Durante, Jorge Rossi and Maximiliano Perier whose involved in fieldwork assistance at Pen\u0026iacute;nsula Potter. The study was financially and logistically supported by the Direcci\u0026oacute;n Nacional del Ant\u0026aacute;rtico, Instituto Ant\u0026aacute;rtico Argentino. The permit for this work was granted by the Direcci\u0026oacute;n Nacional del Ant\u0026aacute;rtico (Environmental Office). Thanks are also given to the restored Ministerio de Ciencia, Tecnologı́a e Innovaci\u0026oacute;n Productiva de la Naci\u0026oacute;n for the promotion of the scientific Argentinean program and the support to public education. We also want to express our heartfelt gratitude and appreciation to all the healthcare workers and researchers working in the frontline against the pandemic for COVID-19. FS, MSL, JN, and FC are members of CONICET.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable. The whole study was non-invasive for the studied animals.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFAS, SMR, MSL, JN, and FC conceived the ideas and designed the methodology; FAS, MSL, and FC collected and processed the samples; FAS, SMR, and FC analysed the samples and data; FAS, SMR, MSL, and FC led the writing of the manuscript. All authors contributed critically to the drafts and gave final approval for publication.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was not granted.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets used and/or analysed during the current study are available on OSFHOME: \u003ca\u003ehttps://osf.io/bzhq5/?view_only=c7049f30be6b420eb6c38fe91a138543\u003c/a\u003e. The entire DNA sequences of this Acanthocephala will be released on October 17, 2022. Some SEM photographs generated during this study are included in this published article.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eLaskowski Z, Zdzitowiecki K. Acanthocephalans in Sub-Antarctic and Antarctic. In Biodiversity and evolution of parasitic life in the Southern Ocean. Springer, Cham. 2017;p.141\u0026ndash;182.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHern\u0026aacute;ndez-Orts JS, Smales LR, Pinacho-Pinacho CD, Garc\u0026iacute;a-Varela M, Presswell B. Novel morphological and molecular data for \u003cem\u003eCorynosoma hannae\u003c/em\u003e Zdzitowiecki, 1984 (Acanthocephala: Polymorphidae) from teleosts, fish-eating birds and pinnipeds from New Zealand. Parasitol. Int. 2017;66(1):905\u0026ndash;916.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLinstow O. Helminthen von Stidgeorgien. Nach der Ausbeute der deutschen Station von 1882\u0026ndash;1883. Jb Hamb Wiss Anst. 1892;9:59\u0026ndash;77.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJohnston TH, Edmonds S. Acanthocephala from Auckland and Campbell Islands. Rec Dominion Museum. 1953;2:55\u0026ndash;61.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eEdmonds S. Acanthocephala collected by the Australian National Antarctic Research Expedition on Heard Island and Macquarie Island during 1948\u0026ndash;50. Trans R Soc South Aust. 1954;78:141\u0026ndash;144.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZdzitowiecki K. A contribution to the knowledge of morphology of \u003cem\u003eCorynosoma bullosum\u003c/em\u003e (Linstow, 1892) (Acanthocephala). Acta Parasit. Pol. 1986;30:225\u0026ndash;232.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGarc\u0026iacute;a-Varela M, Aznar FJ, P\u0026eacute;rez-Ponce de Le\u0026oacute;n G, Pi\u0026ntilde;ero D, Laclette JP. Molecular phylogeny of Corynosoma L\u0026uuml;he, 1904 (Acanthocephala), based on 5.8 S and internal transcribed spacer sequences. J.Parasitol. 2005; 91(2)345\u0026ndash;352.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFolmer O, Black M, Hoeh W, Lutz R, Vrijenhoek R. 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Parasitol. 2018; 95:447\u0026ndash;454. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s11230-018-9794-0\u003c/span\u003e\u003cspan address=\"10.1007/s11230-018-9794-0\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Acanthocephala, Corynosoma bullosum, cytochrome oxidase 1, Mirounga leonina, Polymorphidae","lastPublishedDoi":"10.21203/rs.3.rs-1879398/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-1879398/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground:\u003c/strong\u003e Previous descriptions of \u003cem\u003eCorynosoma bullosum\u003c/em\u003e (Linstow, 1892) Railliet \u0026amp; Henry, 1907\u003cstrong\u003e \u003c/strong\u003eshow that the specimens vary greatly for the proportions of the different structures of the body, measurements of females and males, number of rows of hooks, egg measurements, among others. Here, we redescribe this species from specimens found in the southern elephant seal (\u003cem\u003eMirounga leonina\u003c/em\u003e) feces, from 25 de Mayo/King George Island. We also provide a molecular characterization, in addition to 5.8s and ITS existing sequences.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eResults: \u003c/strong\u003eWe examined feces collected from 41 elephants in 2016 and 2018. We found 30 adult acanthocephalans in 15 of them (19 females and 11 males). The specimens were identified as belonging to the genus \u003cem\u003eCorynosoma\u003c/em\u003e due to the tubular body with an inflated anterior part forming a thorny disk and the posterior part bearing somatic spines on the ventral surface, and genital spines surrounding the genital pore. The morphology of the individuals corresponded to \u003cem\u003eC. bullosum\u003c/em\u003e: large size, marked sexual dimorphism (females 13.7-20.0mm and males 9.5-13.6mm in length), and proboscis with 16-18 rows of spines with 11-15 spines per row (8-12 apical and 3-4 basal). The molecular profile of two specimens of \u003cem\u003eC. bullosum \u003c/em\u003ewas analysed using cytochrome oxidase 1 (COI). Finally, we inferred phylogenetic relationships of the family Polymorphidae using maximum likelihood (ML) and Bayesian inference (BI).\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eConclusions:\u003c/strong\u003e We provided an updated morphological redescription for \u003cem\u003eC. bullosum\u003c/em\u003e including electron microscopy photographs and molecular data. We also present a summary table showing the great morphological variation of the species. The COI gene sequences revealed that \u003cem\u003eC. bullosum\u003c/em\u003e has low genetic variation and that this species is more closely related to \u003cem\u003eAndracantha sigma\u003c/em\u003e than to the genus \u003cem\u003eCorynosoma\u003c/em\u003e. Our analyses show that it is necessary to perform a phylogenetic study of the family Polymorphidae including all the species.\u003c/p\u003e","manuscriptTitle":"Morphological and molecular updates of Corynosoma bullosum (Linstow, 1892) Raulliet \u0026amp; Henry, 1907 parasitizing southern elephant seals from the Antarctic Peninsula","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2022-08-10 16:23:06","doi":"10.21203/rs.3.rs-1879398/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"50e67447-ca3a-4eb4-960d-7ca56bb434f9","owner":[],"postedDate":"August 10th, 2022","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2022-08-17T05:14:04+00:00","versionOfRecord":[],"versionCreatedAt":"2022-08-10 16:23:06","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-1879398","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-1879398","identity":"rs-1879398","version":["v1"]},"buildId":"-HB7Z8yhvgn0wM9Nzuekk","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}