Morphological characterisation of gill monogeneans (Monogenea: Dactylogyridae) of Enteromius aspilus Boulenger, 1907 and Enteromius guirali Thominot,1886 captured in the Cesala River, Cameroon 

Morphological characterisation of gill monogeneans (Monogenea: Dactylogyridae) of Enteromius aspilus Boulenger, 1907 and Enteromius guirali Thominot,1886 captured in the Cesala River, Cameroon | 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 characterisation of gill monogeneans (Monogenea: Dactylogyridae) of Enteromius aspilus Boulenger, 1907 and Enteromius guirali Thominot,1886 captured in the Cesala River, Cameroon Michel Thierry ONANA NGONO, Jeannette TOMBI, Ivan NDONGO This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8595830/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 9 You are reading this latest preprint version Abstract Monogeneans are fish ectoparasites which infested commonly gill filament. They are characterised by their sclerotized haptoral and genital structures. Morphological study of gill monogeneans was conducted at Lebamzip, Center Region of Cameroon. Fish were caught along Cesala River using fishing rods or gillnets, kept in icebox and transported to the laboratory of parasitology and ecology at University of Yaoundé I. Each monogenean was mounted between slide and coverslip in a drop of GAP mixture. Drawings of the sclerotized structures were made using Corel Draw and measurements were taken on Amscope. Four monogeneans species belonging to the genus Dactylogyrus were inventoried. One new species is described ( D. cesalaensis n. sp. from E. aspilus ) and three described species as follows: D. aspili from E. aspilus ; D. mendehei and D. nyongensis from E. guirali are rediscribed. Each monogenean species presented a filamentous anchor and MCO with a flame type accessory piece. Particularly, D. cesalaensis n. sp. have dorsal bar W-shaped; filamentous hooks; vagina shaped like a dagger blade. For D. aspilus : dorsal bar V-shaped; pair I of hooks most developed without filament; pairs II-VII are filamentous; vagina is a leaf-like piece with spiny ends. Concerning D. mendehei : pair I of hooks without filament; pairs II-VII are filamentous; dorsal bar U-shaped. For D. nyongensis : dorsal bar arched; filamentous hooks; three forms of MCO belonging to the flame type observed; vagina comma-shaped. All encountered monogeneans are classed in the Dactylogyrus wunderi type. Colonisation-extinction phenomena explained the parasitic richness observed during this study. Cameroon freshwater Teleost Monogenea morphology taxonomy Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 INTRODUCTION Monogeneans are fish ectoparasites (flatworms) that live mainly attached on gill filaments and skin (Euzet & Combes, 1980; Řehulková et al., 2023). They are triploblastic metazoans without a coelom, dorsoventrally flattened, non-metamerised body and bilaterally symmetrical. These helminths range in size from ten micrometres to a few millimetres. Monogeneans are characterised by their attachment organ called a haptor, which is differentiated in the posterior region of the body (Řehulková et al., 2023). In addition, these parasite are specifically distinguished by the morphology of their copulatory organs (Wong et al., 2006; Ndongo, 2025). In Cameroon, studies conducted on gill monogeneans (Birgi & Lambert, 1987; Birgi, 1987; Bilong Bilong, 1995; Ndongo, 2025; Onana-Ngono et al., 2024) have contributed to our knowledge of the biodiversity of monogeneans in several fish species. Concerning genus Enteromius Cope, 1867, Birgi & Lambert (1987) described fourteen ( 14 ) monogenean species. Despite these investigations, monogenean fauna of various species of this genus remains poorly understood because the watercourses of certain localities remain unexplored. The aim of this study is to inventory the gill monogeneans of Enteromius aspilus Boulenger, 1907 and Enteromius guirali Thominot, 1886 captured in the Cesala River (Lebamzip, Cameroon). MATERIALS AND METHODS Study setting This study was conducted in Lebamzip, a locality of the Lékié Division, Center Region of Cameroon (Fig. 1 ). Fish were caught along the Cesala River, between 4°24'-4°26' North latitude and 11°28'-11°59' East longitude. Cesala River flows into Sanaga Basin with a width of 2–7 m and a depth of 0.25–0.85 m. Streams such as Kongolo, Mbem-Koula, Mekoro, Bitetama and Noab are some of the tributaries of the Cesala River (Fig. 1 ). Fishing and Conservation of hosts Hosts were caught using fishing rods or landing nets. Once out of the water, fish were sacrificed and stored in a cooler containing ice blocks. All specimens were transported to the Laboratory of Parasitology and Ecology at University of Yaoundé I, and then transferred to a freezer. Methodology for morphological characterisation of monogeneans After thawing, gills of the fish stored in ice were examined filament by filament under a NOVEL binocular stereomicroscope. Monogeneans were collected and mounted between slides and coverslips in a drop of mixture of glycerine and ammonium picrate (GAP; Malmberg, 1957). The preparation was sealed 48 hours later. Photographs of each specimen were taken using an Yvimen optical microscope equipped with the Amscope MU1803 photography device connected to a computer. Based on these photographs, drawings of the sclerotized haptoral and genital parts were produced using Corel Draw X4 (version 14.0.0.701). Their measurements, expressed in micrometre, were taken using Amscope according to Gussev (1962) and Birgi & Lambert (1987), and given on the form: mean ± standard deviation (minimum - maximum). The numbering of the haptoral sclerotized parts were made according to ICOPA IV (Euzet & Prost, 1981). Anchor type was determined in accordance with Gussev (1962). Holotype and paratype were deposited at the Helminthological section of the National Museum of Natural History (MNHN), Paris, France. The remaining specimens have been kept in the collection of Laboratory of Parasitology and Ecology, University of Yaoundé I, Cameroon. Ethical approval This work received ethical approval from the Joint Institutional Review Board for Animal & Human Bioethics (JIRB). Fish capture, conservation and manipulation were carried out in accordance with the protocol approved by CRFD-SVSE ethical clearance No: BTC-JIRB2023-082 for the temporary preservation of fish. Results Dactylogyrus cesalaensis n. sp. (Fig. 3) Type host: Enteromius aspilus Boulenger, 1907 Site on host: Gill filament Type locality: Lebamzip (Cesala River) Type-specimens deposited: Holotype (MNHN HEL2066); paratype (MNHN HEL2067) Number of parasites studied: 06 individuals mounted in GAP mixture Prevalence: 9.43% (05 parasitized hosts out of 53 sampled) Etymology : The specific name refers to Cesala River where the host was captured. Description: Anchors are large, with a tiny outer root and an elongated inner root (inner root length is approximately 5 time the length of outer root). Their blade is straight and robust at the top, then curved, thin and perforated at the base, allowing filaments to pass through, extending to the slightly tapered tip. Dorsal bar W-shaped with two almost symmetrical parts, rounded at their tips and connected at their base by a thin convex piece. Ventral bar is a thin blade. Needles were not observed. All marginal hooks are equipped with a thin filament. MCO composed with a copulatory tube fused to an accessory piece that resembles a small flame. Copulatory tube begins with an oval bulb, makes a clockwise spiral turn before sliding into the accessory piece. Vagina is shaped like a dagger blade with a median vaginal orifice. Measurements : Body: total length= 585.11 ± 31.34 (523-610); greatest width= 95.33 ± 7.23 (86-107). Anchor: inner length = 43.17 ± 0.98 (42-45); outer length= 35.33 ± 0.82 (34-36); outer root length= 2.83 ± 0.41 (2-3); inner root length = 14.67 ± 1.37 (13-16); point length = 13.67 ± 0.82 (13-15). Hooks: pair I= 20.67 ± 0.52 (20-21) long; pair II = 20.43 ± 0.41 (20-21) long; pair III= 20.52 ± 1.22 (19-22) long; pair IV= 20.21 ± 1.33 (19-22) long; pair V= 20.17 ± 0.98 (19-21) long; pair VI= 22.17 ± 0.75 (21-23) long; pair VII = 20.67 ± 1.37 (19-23) long. Dorsal bar: total length= 35.17 ± 2.23 (31-37); median width = 2.33 ± 0.52 (2-3). Ventral bar: total length= 8.51 ± 0.71 (8-9); median width= 1.52 ± 0.71 (1-2). MCO: total straight length= 37.83 ± 1.47 (36-40); tube trace length= 62.33 ± 1.63 (60-64). Vagina: total length of vagina= 32.33 ± 1.37 (30-34). Remarks: Dactylogyrus cesalaensis n. sp. is similar to Dactylogyrus insolitus Birgi & Lambert, 1987 and Dactylogyrus mendehei Birgi & Lambert, 1987, parasites of E. martorelli and E. guirali , respectively, with appearance of MCO. Dactylogyrus cesalaensis n. sp. vagina resembles that of D. insolitus and Dactylogyrus simplex Birgi & Lambert, 1987 found on E. martorelli . This parasite is differentiated from these congeners parasitizing genus Enteromius in the morphology of dorsal bar; the morphology and size of dorsal anchor parts. In addition, the measurements and morphology of the sclerotized structures of Dactylogyrus cesalaensis n. sp. differed from those of D. aspilus , D. mendehei and D. nyongensis described by Birgi & Lambert (1987) on E. aspilus . Dactylogyrus aspili Birgi & Lambert, 1987 (Fig. 4) Type host: Enteromius aspilus Boulenger, 1907 Site on host: Gill filament Type locality: Ebogo (Nyong River) Other locality: Lebamzip (Cesala River) Type-specimens deposited: Holotype (MNHN HEL2063); two paratypes (MNHN HEL2064-2065) Number of parasites studied: 38 individuals mounted in GAP mixture Prevalence: 58.49% (31 parasitized hosts out of 53 sampled) Redescription: Anchor have a tiny outer root and a long inner root (inner root length is approximately 3 time the length of outer root). Their elongated, slightly curved blade is equipped with filaments that extend to the rear of the tip. Dorsal bar broadly V-shaped with two almost symmetrical parts connected medially by a thin and deformable junction. Pair I of hooks, which is the most developed, has a very elongated shaft and a tapered tip without filament. Pairs II-IV are morphologically similar with short shaft and filaments. Needle observed. MCO composed with a copulatory tube attached to a flamed accessory piece. Copulatory tube begins with an oval bulb or ovoid lobe protected by the proximal part of accessory piece; forms a loop and runs along the middle part of the accessory piece. Thick at their base and middle section, accessory piece ended like a hooked blade. Vagina, which is highly sclerotized, composed of a leaf-like piece with spiny ends and a short duct leading to the seminal receptacle. Measurements : Body: total length= 496.01 ± 90.94 (326–597); greatest width= 62.93 ± 10.89 (52–87). Anchor: inner length = 38.81 ± 1.26 (37-41); outer length= 33.80 ± 0.68 (33-35); outer root length= 4.80 ± 0.41 (4-5); inner root length = 15.73 ± 0.88 (14-17); point length = 12.20 ± 0.56 (11-13). Hooks: pair I= 34.12 ± 1.51 (31-37) long; pair II = 15.21 ± 1.01 (13-17) long; pair III= 18.40 ± 2.20 (15-23) long; pair IV= 16.87 ± 2.03 (13-20) long; pair V= 19.03 ± 1.56 (15-22) long; pair VI= 24.33 ± 0.98 (23-26) long; pair VII = 22.20 ± 1.86 (18-25) long. Needle: total length= 9.32 ± 1.07 (7-12). Dorsal bar: total length= 32.27 ± 3.90 (21-38); median width = 1.07 ± 0.26 (1-2). MCO: total straight length= 33.07 ± 0.8 (32-35); tube trace length= 48.40 ± 0.91 (47-50). Vagina: total length of vagina= 27.61 ± 1.80 (25-31). Remarks: Dactylogyrus aspilus is similar to Dactylogyroïdes biradius Birgi & Lambert, 1987 and Dactylogyrus jaei Birgi & Lambert, 1987 found on Enteromius jae Boulenger, 1903 in terms of the shape of the dorsal bar. It easily differs by the morphology and size of anchor, hooks and MCO. Redescribed parasite is also similar to D. insolitus only in terms of the morphology of MCO. Compared to the description of this monogenean, the present work shows points of similarity and difference. Morphology of MCO and hooks are similar to that described in the work of Birgi & Lambert (1987). Although the shape of certain parts of the anchor are identical to those described by our predecessors, filament was observed on this sclerotized structure. In addition, a partition separating the two symmetrically parts of the dorsal bar reported in the initial description was not observed. Vagina was observed and drawn. Measurements of sclerotized parts were smaller than those obtained for the same species in the research carried out by Birgi & Lambert (1987). It appears that illustrations produced during this work complete the description of D. aspili . Dactylogyrus mendehei Birgi & Lambert, 1987 (Fig. 5) Type host: Enteromius guirali Thominot, 1886 Site on host: Gill filament Type locality: Awae (Awout River) Other localities: Ecali (Nyong Basin); Lebamzip (Cesala River) Type-specimen deposited: Paratype (MNHN HEL2087) Number of parasites studied: 11 individuals mounted in GAP mixture Prevalence: 72.72% (8 parasitized hosts out of 11 sampled) Redescription: Anchors have a robust inner root, on size 5 time longer than the length of the outer root. Their blade, equipped with filaments, extends into a tapered tip. Pair of hooks I have a straight spine-shaped blade without filament. Pairs II-VII are morphologically similar (short shank, shaft elongated and curved blade with filaments). Dorsal bar is U-shaped, narrower at the base and with widely open branches. Needle, roughly arched, have a rounded handle and a tapered blade with filament. MCO has a copulatory tube attached to a flame-like accessory piece. Copulatory tube begins with one ovoid lobe fused to the basal part of the accessory piece, then forms a clockwise spiral, extends and emerges at the base of the hooked tip in the form of a small flame. Vagina not observed. Measurements : Body: total length= 545.01 ± 41.49 (497-598); greatest width= 83.25 ± 10.28 (71-94). Anchor: inner length = 43.00 ± 1.41 (41-43); outer length= 28.75 ± 0.50 (28-29); outer root length= 3.50 ± 0.58 (3-4); inner root length = 18.25 ± 0.50 (18-19); point length = 13.25 ± 0.50 (13-14). Hooks: pair I= 13.50 ± 2.08 (11-16) long; pair II = 14.25 ± 2.06 (12-16) long; pair III= 15.75 ± 1.50 (14-17) long; pair IV= 16.50 ± 1.29 (16-18) long; pair V= 18.50 ± 1.29 (17-20) long; pair VI= 16.25 ± 0.96 (15-17) long; pair VII = 17.00 ± 0.82 (16-18) long. Needle: total length= 7.41 ± 0.72 (6-9). Dorsal bar: total length= 42.00 ± 2.58 (41-45); median width= 3.00 ± 0.82 (2-4). MCO: total straight length= 29.50 ± 1.29 (28-31); tube trace length= 46.50 ± 2.38 (44-49). Remarks : Pair I of hooks (straight spine-shaped blade without filaments) differs from that proposed by Birgi & Lambert in 1987 (hook-shaped blade with filaments). Dorsal bar is less wide at the base and anchor are equipped with filaments that extend to the tip. Morphology of anchors and dorsal bars brings the redescribed monogenean closer to the species Dactylogyrus bopeleti Birgi & Lambert, 1987 found on E. martorelli but differs from it on the shape of male copulatory organ. The latter is morphologically similar to the male copulatory organ of D. insolitus , a gill parasite of E. martorelli . The measurements obtained on the haptoral and genital parts were slightly smaller than those obtained by Birgi & Lambert (1987). Drawings of sclerotized structures made during this study complete the description of D. mendehei . Dactylogyrus nyongensis Birgi & Lambert, 1987 (Fig. 6) Type host: Enteromius guirali Thominot, 1886 Site on host: Gill filament Type locality: Awae (Awout River) Other localities: Nkolya (Nyong basin), Lebamzip (Cesala River) Type-specimen deposited: paratype (MNHN HEL2086) Number of parasites studied: 13 individuals mounted in GAP mixture Prevalence: 90.91% (10 parasitized hosts out of 11 sampled) Redescription: Anchors are characterised by a shorter outer root approximately one-fifth of the inner root length. Their blade is thinner and has filaments that extend to the tapered tip. Dorsal bar is arched and more robust in its middle section. Hooks are all morphologically similar (more or less rounded handle, slightly elongated shaft, arched blade with filament). The arched needle have a robust handle and a straight blade with filament. Male copulatory organ composed by a copulatory tube and an accessory piece. Copulatory tube begins with an oval bulb attached to the basal part of the accessory piece. It forms a clockwise spiral around the accessory piece and then extends towards the distal flamed part, which has a lateral spine. Three forms of accessory pieces belonging to the flame type have been observed for this monogenean species, with differences in size at the expansions of the distal part. Vagina is comma-shaped. Measurements : Body: total length= 452.67 ± 19.66 (430-465); greatest width= 78.33 ± 11.15 (70-91). Anchor: inner length = 41.80 ± 3.11 (37-41); outer length= 26.80 ± 2.49 (23-29); outer root length= 3.60 ± 0.55 (3-4); inner root length = 19.00 ± 1.87 (17-21); point length = 11.00 ± 1.58 (9-13). Hooks: pair I= 15.40 ± 2.31 (13-19) long; pair II = 16.40 ± 1.14 (15-18) long; pair III= 14.60 ± 1.34 (13-16) long; pair IV= 16.40 ± 0.89 (15-17) long; pair V= 17.00 ± 0.71 (16-18) long; pair VI= 17.60 ± 1.14 (16-19) long; pair VII = 16.60 ± 1.14 (15-18) long. Needle: total length= (9.25 ± 2.63 (7-13). Dorsal bar: total length= 39.20 ± 4.32 (32-43); median width = 2.80 ± 1.09 (2-4). MCO: total straight length= 27.67 ± 2.08 (26-30); tube trace length= 49.67 ± 3.06 (47-53). Vagina: total length of vagina= 36.33 ± 1.53 (35-38). Remarks : Birgi & Lambert (1987) described this monogenean on E. aspilus and E. guirali . The present redescription shows that hooks, needle and male copulatory organ are similar to the illustrations provided by Birgi & Lambert (1987). The arched dorsal bar is thin and flattened in its middle part in the original description but more robust in this study. Anchor of the individuals used for this redescription is equipped with filaments which run along the tip. Three forms of accessory parts were observed instead of two as presented in the description. The redescribed species is similar to Dactylogyrus kii Birgi & Lambert, 1987 and Dactylogyrus maillardi Birgi & Lambert, 1987, found in Enteromius jae Boulenger, 1906 and E. martorelli respectively, only in terms of the morphology of anchors with reduced shafts and tapered tips. Measurements obtained during this redescription are smaller than those reported in the original description, particularly for hooks, dorsal bar and male copulatory organ. In addition, the comma-shaped vagina was observed during the present study. These morphological aspects complete the description of D. nyongensis . Discussion Four Dactylogyrus were inventoried in Cesala River: D. cesalaensis n. sp., D. aspilus from E. aspilus and D. mendehei , D. nyongensis from E. guirali . Gill monogeneans was previously noted by Birgi & Lambert (1987) on the same fish species caught in southern Cameroon. Observation of D. cesalaensis n. sp. on E. aspilus as well as the absence of D. mendehei and D. nyongensis corroborates Norton & Carpenter (1998), who believe that parasite richness of a host varies in space and time. According to Zharikova (2000), this variability results from the combined action of biotic and abiotic factors in the study area. Furthermore, the heterogeneity and variability of their living environment would certainly lead to changes in the parasitic fauna of fish (Blondel, 1995; Ndongo, 2025). In addition, according to N'Douba (2000), these observations indicate that the occupation of the gill biotope of certain fish species occurs through a phenomenon of colonisation-extinction. Dactylogyrus cesalaensis n. sp., found only on the gills of E. aspilus , currently exhibits oioxenic specificity. This new species has been classified in the flame morphological type defined by Gussev (1976) and Lambert (1977). Birgi & Lambert (1987) had previously grouped D. aspili , D. mendehei , and D. nyongensis into the same MCO type. Based on the anchor classification of Dactylogyridae proposed by Gussev (1962), D. cesalaensis n. sp., D. aspili , D. mendehei and D. nyongensis had been classified to the Dactylogyrus wunderi type. Presence of filaments anchored on the curvature of the blade, extending to the tip, should be added to the diagnosis of D. aspili , D. mendehei , and D. nyongensis . Previous studies have shown that anchors of Dactylogyrus are generally equipped with filaments (Lambert, 1977; Guegan et al., 1988). For these species, various forms of dorsal bars have been observed with varying degrees of similarity to the original descriptions. Concerning D. aspili , although V-shaped as in the first description, the partition connecting the two symmetrically parts in the middle has not been observed. For D. mendehei and D. nyongensis , dorsal bars are arched but less robust, as reported by Birgi & Lambert (1987). Regarding the shape of pair I of hooks, the absence of filaments for D. mendehei was the main difference with the original description. In this study, the measurements of sclerotized haptoral and genital parts of D. aspili , D. mendehei and D. nyongensis were slightly less than those obtained by Birgi & Lambert (1987). Numerous studies have revealed changes in the morphology of the monogenean. In this regard, Allalgua et al. (2022) showed significant differences in body total length, body width, inner root or outer root length of anchor, point length and hook length depending on the season. Mo (1991, 1993), Geets et al. (1999) and Zolovs et al. (2012) found that, changes in abiotic factors (water temperature) influence the size of the attachment system of monogeneans. Other authors believe that the morphology of monogeneans varies with biotic factors (Šimková et al., 2000), geographical area (Zolovs & Kirjušina, 2012) and microhabitat (Zolovs et al., 2016). The morphometric differences observed in the monogeneans studied are thought to be related to abiotic factors inherent to the study area. Declarations Funding: The authors declare that no funds, grants, or other support were received during the preparation of this manuscript. Competing interests: The authors have no competing interests to declare that are relevant to the content of this article. Author contributions: Manuscript was conceptualized and designed by MTON and JT; MTON performed the fieldwork, laboratory, data analysis and wrote the first draft; IN assisted MTON in the laboratory and for data analysis; all authors read and approved the manuscript; JT supervised all the steps. Data availability: All data generated or analysed during this study are included in this published article. References Allalgua, A., Boucenna, I., Menasria, A., Boualleg, C., Bensouilah, M. and Kaouachi, N. (2022). Analyse de la variabilité morphométrique de Dactylogyrus heteromorphus El-Gharbi, 1994 (Monogenea: Dactylogyridae). Bulletin de la Société Zoologique de France 147 (3): 151–157. Bilong Bilong, C.F. (1995). Les monogènes parasites des poissons d’eau douce du Cameroun: biodiversité et spécificité ; biologie des populations inféodées à Hemichromis fasciatus. Thèse de Doctorat d’État, Université de Yaoundé I : 341p. Birgi E. (1987). Monogènes parasites de poissons d’eau douce au Tchad et au Sud Cameroun. Thèse de Doctorat d’État, Université des Sciences et Techniques du Languedoc : 297p. Birgi, E. & Lambert, A. (1987). Les Dactylogyridae (Plathelminthes, Monogenea) des Cyprinidae du genre Barbus du Sud Cameroun. Revue d’Hydrobiologie tropicale 20(1): 37–48. Blondel, J. (1995). Biogéographie. Approche écologique et évolutive. Collection d’Ecologie N°27 Masson 297 p. Euzet, L. & Combes, C. (1980). Les problèmes de l’espèce chez les animaux parasites. Mémoire de la Société Zoologique de France , 40: 239–285. Euzet, L. & Prost, M. (1981). Report of meeting of « Monogenea: problems of systematics, biology and ecology ». In : Slusarski W. (Ed.). Proceedings of the Fourth International Congress of Parasitology (ICOPA IV). Review of Advances in Parasitology. Warsaw: Polish Scientific Publishers pp 1003–1004. Geets, A., Appleby, C. and Ollevier, F. (1999). Host dependent and seasonal variation in opisthaptoral hard parts of Gyrodactylus cf. arcuatus from three Pomatoschistus spp. And G. arcuatus from Gasterosteus aculeatus : a multivariate approach. Parasitology 119(1): 27–40. https://doi/org/10.1017/S0031182099004400 Guegan, J-F., Lambert, A. and Euzet, L. (1988). Étude des Monogènes des Cyprinidae du genre Labeo en Afrique de l’Ouest (1), I. Genre Dactylogyrus Diesing, 1850. Revue Hydrobiologie tropicale 21(2): 135–151. Gussev, A.V. (1962). Monogenoidea. In: Bychovskaya-Pavlovskaya, I. E, et al. (Ed.), Key to parasites freshwater fish of the USSR. Moscow-Leningrad: Academya Nauk SSSR , 919p. Gussev, A.V. (1976). Freshwater lndian Monogenoidea. Principes of systematics, analysis of the world faunas and their evolution. Indian Journal of Helminthology . XXV-XXVI (1973–1974): 1-241. Lambert, A. (1977). Les Monogènes Monopisthocotylea parasites des Poissons d'eau douce de la France méditerranéenne. Bulletin du Museum National d'Histoire Naturelle 299(3): 177–214. Malmberg, G. (1957). On the occurrence of Gyrodactylus on Swedish fishes. Skr Utg Södra Sver Fisk Föreningen 1956:19–76 (In Swedish with English abstract and species descriptions). Mo, T.A. (1991). Seasonal variations of opisthaptoral hard parts of Gyrodactylus salaries Malmberg, 1957 (Monogenea: Gyrodactylidae) on parr of Atlantic salmon Salmo salar L. in the River Batnfj ordselva, Norway. Systematic Parasitology 19: 231–240. Mo, T.A. (1993). Seasonal variations of the opisthaptoral hard parts of Gyrodactylus derjavini Mikailov, 1975 (Monogenea: Gyrodactylidae) on brown trout Salmo trutta L. parr and Atlantic salmon S. salar L. parr in the River Sandvikselva, Norway. Systematic Parasitology 26 (3): 225–231. Ndongo, I. (2025). Faunistique et bio-écologie des monogènes branchiaux de quatre Characiformes (Poissons-Téléostéens) dans les régions du Centre et du Lithoral, Cameroun. Thèse de Doctorat/PhD, Université de Yaoundé I. 185p. N’Douba, V. (2000). Biodiversité des monogènes parasites des poissons d'eau douce de côte d’ivoire: cas des poissons des rivières Bia et Agnebi. Thèse de doctorat Université de cocody Abidjan : 225p. Norton, D.A. & Carpenter, M.A. (1998). Mistletoes as parasites: host specificity and speciation. Trends in Ecology & Evolution 13(3): 101–105. https://doi.org/10.1016/S0169-5347(97)01243-3 Onana, N.M.T., Ndongo, I. and Tombi, J. (2023). Structure of the Gill Biotope of Enteromius guirali Thominot, 1886 (Pisces: Cyprinidae) in the Center Region of Cameroon. Journal of Aquaculture and Fisheries 7: 062. https://doi.org/10.24966/AAF-5523/100062 Onana-Ngono, M.T., Ndongo, I. and Tombi, J. (2024). Some ecological aspects of Monogeneans (Platyhelminthes) ectoparasites of Enteromius guirali Thominot, 1886 (Pisces: Cyprinidae) from Cesala River in Cameroon. Parasitology Research 123: 374. https://doi.org/10.1007/s00436-024-08379-8 Řehulková, E., Seifertová, M., Francová, K. and Šimková, A. (2023). Nearctic Dactylogyrus (Playhelminthes, Monogenea) parasitizing cypriniform fishes in the context of morphology and phylogeny, with descriptions of seven new species. Parasite 30 (30). https://doi.org/10.1051/parasite/2023032 Šimková, A., Desdevises, Y., Gelnar, M. and Morand, S. (2000). Co-existence of nine gill ectoparasites (Dactylogyrus: Monogenea) parasitising the roach ( Rutilus rutilus L.): history and present ecology. International Journal Parasitology 30(10):1077–1088. Wong, W.L., Tan, W.B. and Lim, L.H.S. (2006). Sodium dodecyl sulphate as a rapid clearing agent for studying the hard parts of monogeneans and nematodes. Journal of Helminthology. 80(1): 87–90. Zharikova, T.I. (2000). The adaptive reactions of the gill ectoparasites of the bream ( Abramis brama ) and of the white ( Blicca bjoerkna ) to exposure to an anthropogenic factor in the Ivan’Kovo reservoir. Parasitologia 34(1): 50–55. Zolovs, M. & Kirjušina, M. (2012). The attachment apparatus and copulatory organ morphometric differences between Dactylogyrus crucifer Wagener, 1857 (Monogenea: Dactylogyridae) from lake and river environments. Acta Biologica Universitatis Daugavpiliensis 12(1): 106–112. Zolovs, M., Ozuna, A. and Kirjušina, M. (2012). Seasonal variation of attachment apparatus and copulatory organ morphometric variables of Dactylogyrus crucifer Wagener, 1857 (Monogenea: Dactylogyridae) on the gills of roach ( Rutilus rutilus L.) in Latvian water bodies. Acta Biologica Universitatis Daugavpiliensis 12(2): 191–198. Zolovs, M., Deksne, G., Daukste, J., Aizups, J. and Kirjušina, M. (2016). Morphometric analysis of the hard parts of Pseudodactylogyrus anguillae and Pseudodactylogyrus bini (Monogenea: Dactylogyridae) on the gill apparatus of the European eels ( Anguilla anguilla ) from the fresh waters of Latvia. The Journal of Parasitology 102(3): 388–394. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 10 Mar, 2026 Reviews received at journal 10 Mar, 2026 Reviews received at journal 07 Feb, 2026 Reviewers agreed at journal 07 Feb, 2026 Reviewers agreed at journal 28 Jan, 2026 Reviewers invited by journal 20 Jan, 2026 Editor assigned by journal 16 Jan, 2026 Submission checks completed at journal 16 Jan, 2026 First submitted to journal 13 Jan, 2026 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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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-8595830","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":577727391,"identity":"097b7b1f-3d77-4895-86bf-ae7812b3be20","order_by":0,"name":"Michel Thierry ONANA NGONO","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA9klEQVRIiWNgGAWjYDACZgY2BoYCMJPxwYcKkAhzAxFaDCBMwxlnQBQjAS0MCC1s0pxtYNvwa9FtZ3724IPBHbt+6eZj0ozzaqP524FaflRsw6nF7DCbueEMg2fJM+ccS7Yu3HY8d8ZhxgbGnjO38WjhYZPmMTicbHAjx/D2zG3HchuAWpgZ2who+QPRYiDNO+dY7nyitDAYHLYDajGS5m2oyd1AWAubmWSPweEEyRlpyYYzjh3I3QjUchCvX84ffibxo+KwPb9E8sEHH2rqcuedP3zwwY8K3FpgILEBQh8GkwcIqgcCeyhdR4ziUTAKRsEoGGEAAHWjXDKkfjOPAAAAAElFTkSuQmCC","orcid":"","institution":"University of Yaoundé I","correspondingAuthor":true,"prefix":"","firstName":"Michel","middleName":"Thierry ONANA","lastName":"NGONO","suffix":""},{"id":577727392,"identity":"7a760f27-0ccc-4176-a1ef-2d329891b64a","order_by":1,"name":"Jeannette TOMBI","email":"","orcid":"","institution":"University of Yaoundé 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08:42:32","extension":"html","order_by":16,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":100326,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-8595830/v1/8a06955e0dfa1cbd7c44eaa3.html"},{"id":100867683,"identity":"55db5c60-6897-4dac-bc7f-88872dca7c5f","added_by":"auto","created_at":"2026-01-22 08:42:34","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":1089580,"visible":true,"origin":"","legend":"\u003cp\u003eGeographical location of sampling points (Onana et al., 2023)\u003c/p\u003e","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-8595830/v1/349436c3e7018d709a963a6c.png"},{"id":100867687,"identity":"260a4dde-a6fb-4fb0-a848-f9f009c9b9e3","added_by":"auto","created_at":"2026-01-22 08:42:34","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":85084,"visible":true,"origin":"","legend":"\u003cp\u003eGeneral scheme of measurements for sclerotized haptoral and genital parts of monogeneans according to Gussev (1962). (A) Anchor: a= inner length; b= outer length; c= outer root length; d= inner root length; e= point length. (H) Hooks: h= total length. (VB) ventral and (DB) dorsal bar: x= total length; w= median width. (MCO) Male copulatory organ: la= total straight length; lc= tube trace length. (Vg) Vagina: lva= total length of vagina.\u003c/p\u003e","description":"","filename":"floatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-8595830/v1/0e808f52caeb597da881ce2c.png"},{"id":100867690,"identity":"507a3b6c-6d71-49f2-8bc5-2db4569b0b3b","added_by":"auto","created_at":"2026-01-22 08:42:34","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":112336,"visible":true,"origin":"","legend":"\u003cp\u003eSclerotized parts of Dactylogyrus cesalaensis n. sp.. A: haptor; DB= dorsal bar; VB= ventral bar; I-VII= hooks; MCO: male copulatory organ; Vg: vagina\u003c/p\u003e","description":"","filename":"floatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-8595830/v1/bf0946f262ea076dfd9e55e6.png"},{"id":100867663,"identity":"52f0bc17-c8db-4a89-b680-aa0b5f197eeb","added_by":"auto","created_at":"2026-01-22 08:42:26","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":75854,"visible":true,"origin":"","legend":"\u003cp\u003eSclerotized parts of Dactylogyrus aspili. A= haptor; MCO= male copulatory organ; BD = dorsal bar; G = anchor; I-VII = hooks; R= Needle; Vg= vagina\u003c/p\u003e","description":"","filename":"floatimage4.png","url":"https://assets-eu.researchsquare.com/files/rs-8595830/v1/d8fe0d1fead41992e5c0d495.png"},{"id":100867696,"identity":"4a11ee39-2aff-4fa5-8cc2-ff2196fbfa60","added_by":"auto","created_at":"2026-01-22 08:42:38","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":109408,"visible":true,"origin":"","legend":"\u003cp\u003eSclerotized parts of Dactylogyrus mendehei. A= haptor; DB= dorsal bar; I-VII = hooks; MCO= male copulatory organ; R = needle.\u003c/p\u003e","description":"","filename":"floatimage5.png","url":"https://assets-eu.researchsquare.com/files/rs-8595830/v1/507f1fbcae7152456e1a5e18.png"},{"id":100867618,"identity":"71868b01-6dd3-454d-a9b8-145cebefadca","added_by":"auto","created_at":"2026-01-22 08:42:24","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":116455,"visible":true,"origin":"","legend":"\u003cp\u003eSclerotized parts of Dactylogyrus nyongensis. A= haptor; DB= dorsal bar; I-VII= hooks; MCO= male copulatory organs; R= needle; Vg= vagina\u003c/p\u003e","description":"","filename":"floatimage6.png","url":"https://assets-eu.researchsquare.com/files/rs-8595830/v1/2f6096d1fb11b6aa4ee9a468.png"},{"id":101398818,"identity":"0292a606-e768-41d5-ba95-b201d0b294e8","added_by":"auto","created_at":"2026-01-29 09:48:23","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2289471,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8595830/v1/0b130040-efb4-451b-ac28-ef7b0987d78b.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Morphological characterisation of gill monogeneans (Monogenea: Dactylogyridae) of Enteromius aspilus Boulenger, 1907 and Enteromius guirali Thominot,1886 captured in the Cesala River, Cameroon ","fulltext":[{"header":"INTRODUCTION","content":"\u003cp\u003eMonogeneans are fish ectoparasites (flatworms) that live mainly attached on gill filaments and skin (Euzet \u0026amp; Combes, 1980; Řehulkov\u0026aacute; et al., 2023). They are triploblastic metazoans without a coelom, dorsoventrally flattened, non-metamerised body and bilaterally symmetrical. These helminths range in size from ten micrometres to a few millimetres. Monogeneans are characterised by their attachment organ called a haptor, which is differentiated in the posterior region of the body (Řehulkov\u0026aacute; et al., 2023). In addition, these parasite are specifically distinguished by the morphology of their copulatory organs (Wong et al., 2006; Ndongo, 2025).\u003c/p\u003e \u003cp\u003eIn Cameroon, studies conducted on gill monogeneans (Birgi \u0026amp; Lambert, 1987; Birgi, 1987; Bilong Bilong, 1995; Ndongo, 2025; Onana-Ngono et al., 2024) have contributed to our knowledge of the biodiversity of monogeneans in several fish species. Concerning genus \u003cem\u003eEnteromius\u003c/em\u003e Cope, 1867, Birgi \u0026amp; Lambert (1987) described fourteen (\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e) monogenean species. Despite these investigations, monogenean fauna of various species of this genus remains poorly understood because the watercourses of certain localities remain unexplored. The aim of this study is to inventory the gill monogeneans of \u003cem\u003eEnteromius aspilus\u003c/em\u003e Boulenger, 1907 and \u003cem\u003eEnteromius guirali\u003c/em\u003e Thominot, 1886 captured in the Cesala River (Lebamzip, Cameroon).\u003c/p\u003e"},{"header":"MATERIALS AND METHODS","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStudy setting\u003c/h2\u003e \u003cp\u003eThis study was conducted in Lebamzip, a locality of the L\u0026eacute;ki\u0026eacute; Division, Center Region of Cameroon (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Fish were caught along the Cesala River, between 4\u0026deg;24'-4\u0026deg;26' North latitude and 11\u0026deg;28'-11\u0026deg;59' East longitude. Cesala River flows into Sanaga Basin with a width of 2\u0026ndash;7 m and a depth of 0.25\u0026ndash;0.85 m. Streams such as Kongolo, Mbem-Koula, Mekoro, Bitetama and Noab are some of the tributaries of the Cesala River (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eFishing and Conservation of hosts\u003c/h3\u003e\n\u003cp\u003eHosts were caught using fishing rods or landing nets. Once out of the water, fish were sacrificed and stored in a cooler containing ice blocks. All specimens were transported to the Laboratory of Parasitology and Ecology at University of Yaound\u0026eacute; I, and then transferred to a freezer.\u003c/p\u003e\n\u003ch3\u003eMethodology for morphological characterisation of monogeneans\u003c/h3\u003e\n\u003cp\u003eAfter thawing, gills of the fish stored in ice were examined filament by filament under a NOVEL binocular stereomicroscope. Monogeneans were collected and mounted between slides and coverslips in a drop of mixture of glycerine and ammonium picrate (GAP; Malmberg, 1957). The preparation was sealed 48 hours later. Photographs of each specimen were taken using an Yvimen optical microscope equipped with the Amscope MU1803 photography device connected to a computer. Based on these photographs, drawings of the sclerotized haptoral and genital parts were produced using Corel Draw X4 (version 14.0.0.701). Their measurements, expressed in micrometre, were taken using Amscope according to Gussev (1962) and Birgi \u0026amp; Lambert (1987), and given on the form: mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation (minimum - maximum). The numbering of the haptoral sclerotized parts were made according to ICOPA IV (Euzet \u0026amp; Prost, 1981). Anchor type was determined in accordance with Gussev (1962). Holotype and paratype were deposited at the Helminthological section of the National Museum of Natural History (MNHN), Paris, France. The remaining specimens have been kept in the collection of Laboratory of Parasitology and Ecology, University of Yaound\u0026eacute; I, Cameroon.\u003c/p\u003e \u003cp\u003e\u003cstrong\u003eEthical approval\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis work received ethical approval from the Joint Institutional Review Board for Animal \u0026amp; Human Bioethics (JIRB). Fish capture, conservation and manipulation were carried out in accordance with the protocol approved by CRFD-SVSE ethical clearance No: BTC-JIRB2023-082 for the temporary preservation of fish.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003e\u003cstrong\u003e\u003cem\u003eDactylogyrus cesalaensis\u003c/em\u003e n. sp.\u0026nbsp;\u003c/strong\u003e(Fig. 3)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eType host:\u003c/strong\u003e \u003cem\u003eEnteromius aspilus\u003c/em\u003e Boulenger, 1907\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSite on host:\u003c/strong\u003e Gill filament\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eType locality:\u003c/strong\u003e Lebamzip (Cesala River)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eType-specimens deposited:\u0026nbsp;\u003c/strong\u003eHolotype (MNHN HEL2066); paratype (MNHN HEL2067)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eNumber of parasites studied:\u003c/strong\u003e 06 individuals mounted in GAP mixture\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePrevalence:\u003c/strong\u003e 9.43% (05 parasitized hosts out of 53 sampled)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEtymology\u003c/strong\u003e: The specific name refers to Cesala River where the host was captured.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDescription:\u0026nbsp;\u003c/strong\u003eAnchors are large, with a tiny outer root and an elongated inner root (inner root length is approximately 5 time the length of outer root). Their blade is straight and robust at the top, then curved, thin and perforated at the base, allowing filaments to pass through, extending to the slightly tapered tip. Dorsal bar W-shaped with two almost symmetrical parts, rounded at their tips and connected at their base by a thin convex piece. Ventral bar is a thin blade. Needles were not observed. All marginal hooks are equipped with a thin filament. MCO composed with a copulatory tube fused to an accessory piece that resembles a small flame. Copulatory tube begins with an oval bulb, makes a clockwise spiral turn before sliding into the accessory piece. Vagina is shaped like a dagger blade with a median vaginal orifice.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMeasurements\u003c/strong\u003e: Body: total length= 585.11 \u0026plusmn; 31.34 (523-610); greatest width= 95.33 \u0026plusmn; 7.23 (86-107). Anchor: inner length = 43.17 \u0026plusmn; 0.98 (42-45); outer length= 35.33 \u0026plusmn; 0.82 (34-36); outer root length= 2.83 \u0026plusmn; 0.41 (2-3); inner root length = 14.67 \u0026plusmn; 1.37 (13-16); point length = 13.67 \u0026plusmn; 0.82 (13-15). Hooks: pair I= 20.67 \u0026plusmn; 0.52 (20-21) long; pair II = 20.43 \u0026plusmn; 0.41 (20-21) long; pair III= 20.52 \u0026plusmn; 1.22 (19-22) long; pair IV= 20.21 \u0026plusmn; 1.33 (19-22) long; pair V= 20.17 \u0026plusmn; 0.98 (19-21) long; pair VI= 22.17 \u0026plusmn; 0.75 (21-23) long; pair VII = 20.67 \u0026plusmn; 1.37 (19-23) long. \u0026nbsp;Dorsal bar: total length= 35.17 \u0026plusmn; 2.23 (31-37); median width = 2.33 \u0026plusmn; 0.52 (2-3). Ventral bar: total length= 8.51 \u0026plusmn; 0.71 (8-9); median width= 1.52 \u0026plusmn; 0.71 (1-2). MCO: total straight length= 37.83 \u0026plusmn; 1.47 (36-40); tube trace length= 62.33 \u0026plusmn; 1.63 (60-64). Vagina: total length of vagina= 32.33 \u0026plusmn; 1.37 (30-34).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eRemarks:\u003c/strong\u003e \u003cem\u003eDactylogyrus cesalaensis\u003c/em\u003e n. sp. is similar to \u003cem\u003eDactylogyrus insolitus\u003c/em\u003e Birgi \u0026amp; Lambert, 1987 and \u003cem\u003eDactylogyrus mendehei\u003c/em\u003e Birgi \u0026amp; Lambert, 1987, parasites of \u003cem\u003eE. martorelli\u003c/em\u003e and \u003cem\u003eE. guirali\u003c/em\u003e, respectively, with appearance of MCO. \u003cem\u003eDactylogyrus cesalaensis\u003c/em\u003e n. sp. vagina resembles that of \u003cem\u003eD. insolitus\u003c/em\u003e and \u003cem\u003eDactylogyrus simplex\u003c/em\u003e Birgi \u0026amp; Lambert, 1987 found on \u003cem\u003eE. martorelli\u003c/em\u003e. This parasite\u003cem\u003e\u0026nbsp;\u003c/em\u003eis differentiated from these congeners parasitizing genus \u003cem\u003eEnteromius\u003c/em\u003e in the morphology of dorsal bar; the morphology and size of dorsal anchor parts. In addition, the measurements and morphology of the sclerotized structures of\u003cem\u003e\u0026nbsp;Dactylogyrus cesalaensis\u003c/em\u003e n. sp. differed from those of \u003cem\u003eD. aspilus\u003c/em\u003e, \u003cem\u003eD. mendehei\u003c/em\u003e and \u003cem\u003eD. nyongensis\u0026nbsp;\u003c/em\u003edescribed by Birgi \u0026amp; Lambert (1987) on \u003cem\u003eE. aspilus\u003c/em\u003e.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eDactylogyrus aspili\u003c/em\u003e Birgi \u0026amp; Lambert, 1987\u0026nbsp;\u003c/strong\u003e(Fig. 4)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eType host:\u003c/strong\u003e \u003cem\u003eEnteromius aspilus\u003c/em\u003e Boulenger, 1907\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSite on host:\u003c/strong\u003e Gill filament\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eType locality:\u003c/strong\u003e Ebogo (Nyong River)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eOther locality:\u003c/strong\u003e Lebamzip (Cesala River)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eType-specimens deposited:\u003c/strong\u003e Holotype (MNHN HEL2063); two paratypes (MNHN HEL2064-2065)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eNumber of parasites studied:\u003c/strong\u003e 38 individuals mounted in GAP mixture\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePrevalence:\u003c/strong\u003e 58.49% (31 parasitized hosts out of 53 sampled)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eRedescription:\u0026nbsp;\u003c/strong\u003eAnchor have a tiny outer root and a long inner root (inner root length is approximately 3 time the length of outer root). Their elongated, slightly curved blade is equipped with filaments that extend to the rear of the tip. Dorsal bar broadly V-shaped with two almost symmetrical parts connected medially by a thin and deformable junction. Pair I of hooks, which is the most developed, has a very elongated shaft and a tapered tip without filament. Pairs II-IV are morphologically similar with short shaft and filaments. Needle observed. MCO composed with a copulatory tube attached to a flamed accessory piece. Copulatory tube begins with an oval bulb or ovoid lobe protected by the proximal part of accessory piece; forms a loop and runs along the middle part of the accessory piece. Thick at their base and middle section, accessory piece ended like a hooked blade. Vagina, which is highly sclerotized, composed of a leaf-like piece with spiny ends and a short duct leading to the seminal receptacle.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMeasurements\u003c/strong\u003e: Body: total length= 496.01 \u0026plusmn; 90.94 (326\u0026ndash;597); greatest width= 62.93 \u0026plusmn; 10.89 (52\u0026ndash;87). Anchor: inner length = 38.81 \u0026plusmn; 1.26 (37-41); outer length= 33.80 \u0026plusmn; 0.68 (33-35); outer root length= 4.80 \u0026plusmn; 0.41 (4-5); inner root length = 15.73 \u0026plusmn; 0.88 (14-17); point length = 12.20 \u0026plusmn; 0.56 (11-13). Hooks: pair I= 34.12 \u0026plusmn; 1.51 (31-37) long; pair II = 15.21 \u0026plusmn; 1.01 (13-17) long; pair III= 18.40 \u0026plusmn; 2.20 (15-23) long; pair IV= 16.87 \u0026plusmn; 2.03 (13-20) long; pair V= 19.03 \u0026plusmn; 1.56 (15-22) long; pair VI= 24.33 \u0026plusmn; 0.98 (23-26) long; pair VII = 22.20 \u0026plusmn; 1.86 (18-25) long. Needle: total length= 9.32 \u0026plusmn; 1.07 (7-12). \u0026nbsp;Dorsal bar: total length= 32.27 \u0026plusmn; 3.90 (21-38); median width = 1.07 \u0026plusmn; 0.26 (1-2). MCO: total straight length= 33.07 \u0026plusmn; 0.8 (32-35); tube trace length= 48.40 \u0026plusmn; 0.91 (47-50). Vagina: total length of vagina= 27.61 \u0026plusmn; 1.80 (25-31).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eRemarks:\u003c/strong\u003e \u003cem\u003eDactylogyrus aspilus\u003c/em\u003e is similar to \u003cem\u003eDactylogyro\u0026iuml;des biradius\u003c/em\u003e Birgi \u0026amp; Lambert, 1987 and \u003cem\u003eDactylogyrus jaei\u003c/em\u003e Birgi \u0026amp; Lambert, 1987 found on \u003cem\u003eEnteromius jae\u003c/em\u003e Boulenger, 1903 in terms of the shape of the dorsal bar. It easily differs by the morphology and size of anchor, hooks and MCO. Redescribed parasite is also similar to \u003cem\u003eD. insolitus\u003c/em\u003e only in terms of the morphology of MCO. Compared to the description of this monogenean, the present work shows points of similarity and difference. Morphology of MCO and hooks are similar to that described in the work of Birgi \u0026amp; Lambert (1987). Although the shape of certain parts of the anchor are identical to those described by our predecessors, filament was observed on this sclerotized structure. In addition, a partition separating the two symmetrically parts of the dorsal bar reported in the initial description was not observed. Vagina was observed and drawn. Measurements of sclerotized parts were smaller than those obtained for the same species in the research carried out by Birgi \u0026amp; Lambert (1987). It appears that illustrations produced during this work complete the description of \u003cem\u003eD. aspili\u003c/em\u003e.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eDactylogyrus mendehei\u003c/em\u003e Birgi \u0026amp; Lambert, 1987\u0026nbsp;\u003c/strong\u003e(Fig. 5)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eType host:\u003c/strong\u003e \u003cem\u003eEnteromius guirali\u003c/em\u003e Thominot, 1886\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSite on host:\u003c/strong\u003e Gill filament\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eType locality:\u003c/strong\u003e Awae (Awout River)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eOther localities:\u003c/strong\u003e Ecali (Nyong Basin); Lebamzip (Cesala River)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eType-specimen deposited:\u0026nbsp;\u003c/strong\u003eParatype (MNHN HEL2087)\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eNumber of parasites studied:\u0026nbsp;\u003c/strong\u003e11 individuals mounted in GAP mixture\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePrevalence:\u0026nbsp;\u003c/strong\u003e72.72% (8 parasitized hosts out of 11 sampled)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eRedescription:\u0026nbsp;\u003c/strong\u003eAnchors have a robust inner root, on size 5 time longer than the length of the outer root. Their blade, equipped with filaments, extends into a tapered tip. Pair of hooks I have a straight spine-shaped blade without filament. Pairs II-VII are morphologically similar (short shank, shaft elongated and curved blade with filaments). Dorsal bar is U-shaped, narrower at the base and with widely open branches. Needle, roughly arched, have a rounded handle and a tapered blade with filament. MCO has a copulatory tube attached to a flame-like accessory piece. Copulatory tube begins with one ovoid lobe fused to the basal part of the accessory piece, then forms a clockwise spiral, extends and emerges at the base of the hooked tip in the form of a small flame. Vagina not observed.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMeasurements\u003c/strong\u003e: Body: total length= 545.01 \u0026plusmn; 41.49 (497-598); greatest width= 83.25 \u0026plusmn; 10.28 (71-94). Anchor: inner length = 43.00 \u0026plusmn; 1.41 (41-43); outer length= 28.75 \u0026plusmn; 0.50 (28-29); outer root length= 3.50 \u0026plusmn; 0.58 (3-4); inner root length = 18.25 \u0026plusmn; 0.50 (18-19); point length = 13.25 \u0026plusmn; 0.50 (13-14). Hooks: pair I= 13.50 \u0026plusmn; 2.08 (11-16) long; pair II = 14.25 \u0026plusmn; 2.06 (12-16) long; pair III= 15.75 \u0026plusmn; 1.50 (14-17) long; pair IV= 16.50 \u0026plusmn; 1.29 (16-18) long; pair V= 18.50 \u0026plusmn; 1.29 (17-20) long; pair VI= 16.25 \u0026plusmn; 0.96 (15-17) long; pair VII = 17.00 \u0026plusmn; 0.82 (16-18) long. Needle: total length= 7.41 \u0026plusmn; 0.72 (6-9). \u0026nbsp;Dorsal bar: total length= 42.00 \u0026plusmn; 2.58 (41-45); median width= 3.00 \u0026plusmn; 0.82 (2-4). MCO: total straight length= 29.50 \u0026plusmn; 1.29 (28-31); tube trace length= 46.50 \u0026plusmn; 2.38 (44-49).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eRemarks\u003c/strong\u003e: Pair I of hooks (straight spine-shaped blade without filaments) differs from that proposed by Birgi \u0026amp; Lambert in 1987 (hook-shaped blade with filaments). Dorsal bar is less wide at the base and anchor are equipped with filaments that extend to the tip. Morphology of anchors and dorsal bars brings the redescribed monogenean closer to the species \u003cem\u003eDactylogyrus bopeleti\u003c/em\u003e Birgi \u0026amp; Lambert, 1987 found on \u003cem\u003eE. martorelli\u003c/em\u003e but differs from it on the shape of male copulatory organ. The latter is morphologically similar to the male copulatory organ of \u003cem\u003eD. insolitus\u003c/em\u003e, a gill parasite of \u003cem\u003eE. martorelli\u003c/em\u003e. The measurements obtained on the haptoral and genital parts were slightly smaller than those obtained by Birgi \u0026amp; Lambert (1987). Drawings of sclerotized structures made during this study complete the description of \u003cem\u003eD. mendehei\u003c/em\u003e.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eDactylogyrus nyongensis\u003c/em\u003e Birgi \u0026amp; Lambert, 1987\u003c/strong\u003e (Fig. 6)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eType host:\u003c/strong\u003e \u003cem\u003eEnteromius guirali\u003c/em\u003e Thominot, 1886\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSite on host:\u003c/strong\u003e Gill filament\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eType locality:\u003c/strong\u003e Awae (Awout River)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eOther localities:\u003c/strong\u003e Nkolya (Nyong basin), Lebamzip (Cesala River)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eType-specimen deposited:\u0026nbsp;\u003c/strong\u003eparatype (MNHN HEL2086)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eNumber of parasites studied:\u003c/strong\u003e 13 individuals mounted in GAP mixture\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePrevalence:\u003c/strong\u003e 90.91% (10 parasitized hosts out of 11 sampled)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eRedescription:\u003c/strong\u003e Anchors are characterised by a shorter outer root approximately one-fifth of the inner root length. Their blade is thinner and has filaments that extend to the tapered tip. Dorsal bar is arched and more robust in its middle section. Hooks are all morphologically similar (more or less rounded handle, slightly elongated shaft, arched blade with filament). The arched needle have a robust handle and a straight blade with filament. Male copulatory organ composed by a copulatory tube and an accessory piece. Copulatory tube begins with an oval bulb attached to the basal part of the accessory piece. It forms a clockwise spiral around the accessory piece and then extends towards the distal flamed part, which has a lateral spine. Three forms of accessory pieces belonging to the flame type have been observed for this monogenean species, with differences in size at the expansions of the distal part. Vagina is comma-shaped.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMeasurements\u003c/strong\u003e: Body: total length= 452.67 \u0026plusmn; 19.66 (430-465); greatest width= 78.33 \u0026plusmn; 11.15 (70-91). Anchor: inner length = 41.80 \u0026plusmn; 3.11 (37-41); outer length= 26.80 \u0026plusmn; 2.49 (23-29); outer root length= 3.60 \u0026plusmn; 0.55 (3-4); inner root length = 19.00 \u0026plusmn; 1.87 (17-21); point length = 11.00 \u0026plusmn; 1.58 (9-13). Hooks: pair I= 15.40 \u0026plusmn; 2.31 (13-19) long; pair II = 16.40 \u0026plusmn; 1.14 (15-18) long; pair III= 14.60 \u0026plusmn; 1.34 (13-16) long; pair IV= 16.40 \u0026plusmn; 0.89 (15-17) long; pair V= 17.00 \u0026plusmn; 0.71 (16-18) long; pair VI= 17.60 \u0026plusmn; 1.14 (16-19) long; pair VII = 16.60 \u0026plusmn; 1.14 (15-18) long. Needle: total length= (9.25 \u0026plusmn; 2.63 (7-13). \u0026nbsp; Dorsal bar: total length= 39.20 \u0026plusmn; 4.32 (32-43); median width = 2.80 \u0026plusmn; 1.09 (2-4). MCO: total straight length= 27.67 \u0026plusmn; 2.08 (26-30); tube trace length= 49.67 \u0026plusmn; 3.06 (47-53). Vagina: total length of vagina= 36.33 \u0026plusmn; 1.53 (35-38).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eRemarks\u003c/strong\u003e: Birgi \u0026amp; Lambert (1987) described this monogenean on \u003cem\u003eE. aspilus\u003c/em\u003e and \u003cem\u003eE. guirali\u003c/em\u003e. The present redescription shows that hooks, needle and male copulatory organ are similar to the illustrations provided by Birgi \u0026amp; Lambert (1987). The arched dorsal bar is thin and flattened in its middle part in the original description but more robust in this study. Anchor of the individuals used for this redescription is equipped with filaments which run along the tip. Three forms of accessory parts were observed instead of two as presented in the description. The redescribed species is similar to \u003cem\u003eDactylogyrus kii\u003c/em\u003e Birgi \u0026amp; Lambert, 1987 and \u003cem\u003eDactylogyrus maillardi\u003c/em\u003e Birgi \u0026amp; Lambert, 1987, found in \u003cem\u003eEnteromius jae\u003c/em\u003e Boulenger, 1906 and \u003cem\u003eE. martorelli\u003c/em\u003e respectively, only in terms of the morphology of anchors with reduced shafts and tapered tips. Measurements obtained during this redescription are smaller than those reported in the original description, particularly for hooks, dorsal bar and male copulatory organ. In addition, the comma-shaped vagina was observed during the present study. These morphological aspects complete the description of \u003cem\u003eD. nyongensis\u003c/em\u003e.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eFour \u003cem\u003eDactylogyrus\u0026nbsp;\u003c/em\u003ewere inventoried in Cesala River: \u003cem\u003eD. cesalaensis\u0026nbsp;\u003c/em\u003en. sp., \u003cem\u003eD. aspilus\u003c/em\u003e from \u003cem\u003eE. aspilus\u0026nbsp;\u003c/em\u003eand \u003cem\u003eD. mendehei\u003c/em\u003e, \u003cem\u003eD. nyongensis\u003c/em\u003e from \u003cem\u003eE. guirali\u003c/em\u003e. Gill monogeneans was previously noted by Birgi \u0026amp; Lambert (1987) on the same fish species caught in southern Cameroon. Observation of \u003cem\u003eD. cesalaensis\u0026nbsp;\u003c/em\u003en. sp. on \u003cem\u003eE. aspilus\u003c/em\u003e as well as the absence of \u003cem\u003eD. mendehei\u003c/em\u003e and \u003cem\u003eD. nyongensis\u003c/em\u003e corroborates Norton \u0026amp; Carpenter (1998), who believe that parasite richness of a host varies in space and time. According to Zharikova (2000), this variability results from the combined action of biotic and abiotic factors in the study area. Furthermore, the heterogeneity and variability of their living environment would certainly lead to changes in the parasitic fauna of fish (Blondel, 1995; Ndongo, 2025). In addition, according to N\u0026apos;Douba (2000), these observations indicate that the occupation of the gill biotope of certain fish species occurs through a phenomenon of colonisation-extinction.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eDactylogyrus cesalaensis\u003c/em\u003e n. sp., found only on the gills of \u003cem\u003eE. aspilus\u003c/em\u003e, currently exhibits oioxenic specificity. This new species has been classified in the flame morphological type defined by Gussev (1976) and Lambert (1977). Birgi \u0026amp; Lambert (1987) had previously grouped \u003cem\u003eD. aspili\u003c/em\u003e, \u003cem\u003eD. mendehei\u003c/em\u003e, and \u003cem\u003eD. nyongensis\u003c/em\u003e into the same MCO type. Based on the anchor classification of Dactylogyridae proposed by Gussev (1962), \u003cem\u003eD. cesalaensis\u0026nbsp;\u003c/em\u003en. sp., \u003cem\u003eD. aspili\u003c/em\u003e, \u003cem\u003eD. mendehei\u003c/em\u003e and \u003cem\u003eD. nyongensis\u003c/em\u003e had been classified to the \u003cem\u003eDactylogyrus wunderi\u003c/em\u003e type. Presence of filaments anchored on the curvature of the blade, extending to the tip, should be added to the diagnosis of \u003cem\u003eD. aspili\u003c/em\u003e, \u003cem\u003eD. mendehei\u003c/em\u003e, and \u003cem\u003eD. nyongensis\u003c/em\u003e. Previous studies have shown that anchors of \u003cem\u003eDactylogyrus\u003c/em\u003e are generally equipped with filaments (Lambert, 1977; Guegan et al., 1988). For these species, various forms of dorsal bars have been observed with varying degrees of similarity to the original descriptions. Concerning \u003cem\u003eD. aspili\u003c/em\u003e, although V-shaped as in the first description, the partition connecting the two symmetrically parts in the middle has not been observed. For \u003cem\u003eD. mendehei\u003c/em\u003e and \u003cem\u003eD. nyongensis\u003c/em\u003e, dorsal bars are arched but less robust, as reported by Birgi \u0026amp; Lambert (1987). Regarding the shape of pair I of hooks, the absence of filaments for \u003cem\u003eD. mendehei\u003c/em\u003e was the main difference with the original description. In this study, the measurements of sclerotized haptoral and genital parts of \u003cem\u003eD. aspili\u003c/em\u003e, \u003cem\u003eD. mendehei\u003c/em\u003e and \u003cem\u003eD. nyongensis\u003c/em\u003e were slightly less than those obtained by Birgi \u0026amp; Lambert (1987). Numerous studies have revealed changes in the morphology of the monogenean. In this regard, Allalgua et al. (2022) showed significant differences in body total length, body width, inner root or outer root length of anchor, point length and hook length depending on the season. Mo (1991, 1993), Geets et al. (1999) and Zolovs et al. (2012) found that, changes in abiotic factors (water temperature) \u0026nbsp;influence the size of the attachment system of monogeneans. Other authors believe that the morphology of monogeneans varies with biotic factors (\u0026Scaron;imkov\u0026aacute; et al., 2000), geographical area (Zolovs \u0026amp; Kirju\u0026scaron;ina, 2012) and microhabitat (Zolovs et al., 2016). The morphometric differences observed in the monogeneans studied are thought to be related to abiotic factors inherent to the study area.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eFunding:\u003c/strong\u003e The authors declare that no funds, grants, or other support were received during the preparation of this manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests:\u0026nbsp;\u003c/strong\u003eThe authors have no competing interests to declare that are relevant to the content of this article.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contributions:\u003c/strong\u003e Manuscript was conceptualized and designed by MTON and JT; MTON performed the fieldwork, laboratory, data analysis and wrote the first draft; IN assisted MTON in the laboratory and for data analysis; all authors read and approved the manuscript;\u0026nbsp;JT supervised all the steps.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability:\u0026nbsp;\u003c/strong\u003eAll data generated or analysed during this study are included in this published article.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eAllalgua, A., Boucenna, I., Menasria, A., Boualleg, C., Bensouilah, M. and Kaouachi, N. (2022). Analyse de la variabilit\u0026eacute; morphom\u0026eacute;trique de \u003cem\u003eDactylogyrus heteromorphus\u003c/em\u003e El-Gharbi, 1994 (Monogenea: Dactylogyridae). \u003cem\u003eBulletin de la Soci\u0026eacute;t\u0026eacute; Zoologique de France\u003c/em\u003e 147 (3): 151\u0026ndash;157.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBilong Bilong, C.F. (1995). Les monog\u0026egrave;nes parasites des poissons d\u0026rsquo;eau douce du Cameroun: biodiversit\u0026eacute; et sp\u0026eacute;cificit\u0026eacute; ; biologie des populations inf\u0026eacute;od\u0026eacute;es \u0026agrave; \u003cem\u003eHemichromis fasciatus.\u003c/em\u003e Th\u0026egrave;se de Doctorat d\u0026rsquo;\u0026Eacute;tat, \u003cem\u003eUniversit\u0026eacute; de Yaound\u0026eacute; I\u003c/em\u003e: 341p.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBirgi E. (1987). Monog\u0026egrave;nes parasites de poissons d\u0026rsquo;eau douce au Tchad et au Sud Cameroun. Th\u0026egrave;se de Doctorat d\u0026rsquo;\u0026Eacute;tat, \u003cem\u003eUniversit\u0026eacute; des Sciences et Techniques du Languedoc\u003c/em\u003e : 297p.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBirgi, E. \u0026amp; Lambert, A. (1987). Les \u003cem\u003eDactylogyridae\u003c/em\u003e (Plathelminthes, Monogenea) des \u003cem\u003eCyprinidae\u003c/em\u003e du genre \u003cem\u003eBarbus\u003c/em\u003e du Sud Cameroun. \u003cem\u003eRevue d\u0026rsquo;Hydrobiologie tropicale\u003c/em\u003e 20(1): 37\u0026ndash;48.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBlondel, J. (1995). Biog\u0026eacute;ographie. Approche \u0026eacute;cologique et \u0026eacute;volutive. \u003cem\u003eCollection d\u0026rsquo;Ecologie\u003c/em\u003e N\u0026deg;27 Masson 297 p.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eEuzet, L. \u0026amp; Combes, C. (1980). Les probl\u0026egrave;mes de l\u0026rsquo;esp\u0026egrave;ce chez les animaux parasites. \u003cem\u003eM\u0026eacute;moire de la Soci\u0026eacute;t\u0026eacute; Zoologique de France\u003c/em\u003e, 40: 239\u0026ndash;285.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eEuzet, L. \u0026amp; Prost, M. (1981). Report of meeting of \u0026laquo; Monogenea: problems of systematics, biology and ecology \u0026raquo;. \u003cem\u003eIn\u003c/em\u003e: Slusarski W. (Ed.). Proceedings of the Fourth International Congress of Parasitology (ICOPA IV). Review of Advances in Parasitology. \u003cem\u003eWarsaw: Polish Scientific Publishers\u003c/em\u003e pp 1003\u0026ndash;1004.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGeets, A., Appleby, C. and Ollevier, F. (1999). Host dependent and seasonal variation in opisthaptoral hard parts of \u003cem\u003eGyrodactylus\u003c/em\u003e cf. arcuatus from three \u003cem\u003ePomatoschistus\u003c/em\u003e spp. And \u003cem\u003eG. arcuatus\u003c/em\u003e from \u003cem\u003eGasterosteus aculeatus\u003c/em\u003e: a multivariate approach. \u003cem\u003eParasitology\u003c/em\u003e 119(1): 27\u0026ndash;40. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi/org/10.1017/S0031182099004400\u003c/span\u003e\u003cspan address=\"https://doi/10.1017/S0031182099004400\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGuegan, J-F., Lambert, A. and Euzet, L. (1988). \u0026Eacute;tude des Monog\u0026egrave;nes des Cyprinidae du genre \u003cem\u003eLabeo\u003c/em\u003e en Afrique de l\u0026rsquo;Ouest (1), I. Genre \u003cem\u003eDactylogyrus\u003c/em\u003e Diesing, 1850. \u003cem\u003eRevue Hydrobiologie tropicale\u003c/em\u003e 21(2): 135\u0026ndash;151.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGussev, A.V. (1962). Monogenoidea. In: Bychovskaya-Pavlovskaya, I. E, et al. (Ed.), Key to parasites freshwater fish of the USSR. Moscow-Leningrad: \u003cem\u003eAcademya Nauk SSSR\u003c/em\u003e, 919p.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGussev, A.V. (1976). Freshwater lndian Monogenoidea. Principes of systematics, analysis of the world faunas and their evolution. \u003cem\u003eIndian Journal of Helminthology\u003c/em\u003e. XXV-XXVI (1973\u0026ndash;1974): 1-241.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLambert, A. (1977). Les Monog\u0026egrave;nes Monopisthocotylea parasites des Poissons d'eau douce de la France m\u0026eacute;diterran\u0026eacute;enne. \u003cem\u003eBulletin du Museum National d'Histoire Naturelle\u003c/em\u003e 299(3): 177\u0026ndash;214.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMalmberg, G. (1957). On the occurrence of Gyrodactylus on Swedish fishes. Skr Utg S\u0026ouml;dra Sver Fisk F\u0026ouml;reningen 1956:19\u0026ndash;76 (In Swedish with English abstract and species descriptions).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMo, T.A. (1991). Seasonal variations of opisthaptoral hard parts of \u003cem\u003eGyrodactylus salaries\u003c/em\u003e Malmberg, 1957 (Monogenea: Gyrodactylidae) on parr of Atlantic salmon \u003cem\u003eSalmo salar\u003c/em\u003e L. in the River Batnfj ordselva, Norway. \u003cem\u003eSystematic Parasitology\u003c/em\u003e 19: 231\u0026ndash;240.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMo, T.A. (1993). Seasonal variations of the opisthaptoral hard parts of Gyrodactylus derjavini Mikailov, 1975 (Monogenea: Gyrodactylidae) on brown trout \u003cem\u003eSalmo trutta\u003c/em\u003e L. parr and Atlantic salmon \u003cem\u003eS. salar\u003c/em\u003e L. parr in the River Sandvikselva, Norway. \u003cem\u003eSystematic Parasitology\u003c/em\u003e 26 (3): 225\u0026ndash;231.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNdongo, I. (2025). Faunistique et bio-\u0026eacute;cologie des monog\u0026egrave;nes branchiaux de quatre Characiformes (Poissons-T\u0026eacute;l\u0026eacute;ost\u0026eacute;ens) dans les r\u0026eacute;gions du Centre et du Lithoral, Cameroun. Th\u0026egrave;se de Doctorat/PhD, Universit\u0026eacute; de Yaound\u0026eacute; I. 185p.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eN\u0026rsquo;Douba, V. (2000). Biodiversit\u0026eacute; des monog\u0026egrave;nes parasites des poissons d'eau douce de c\u0026ocirc;te d\u0026rsquo;ivoire: cas des poissons des rivi\u0026egrave;res Bia et Agnebi. \u003cem\u003eTh\u0026egrave;se de doctorat Universit\u0026eacute; de cocody Abidjan\u003c/em\u003e : 225p.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNorton, D.A. \u0026amp; Carpenter, M.A. (1998). Mistletoes as parasites: host specificity and speciation. \u003cem\u003eTrends in Ecology \u0026amp; Evolution\u003c/em\u003e 13(3): 101\u0026ndash;105. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/S0169-5347(97)01243-3\u003c/span\u003e\u003cspan address=\"10.1016/S0169-5347(97)01243-3\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eOnana, N.M.T., Ndongo, I. and Tombi, J. (2023). Structure of the Gill Biotope of \u003cem\u003eEnteromius guirali\u003c/em\u003e Thominot, 1886 (Pisces: Cyprinidae) in the Center Region of Cameroon. \u003cem\u003eJournal of Aquaculture and Fisheries\u003c/em\u003e 7: 062. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.24966/AAF-5523/100062\u003c/span\u003e\u003cspan address=\"10.24966/AAF-5523/100062\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eOnana-Ngono, M.T., Ndongo, I. and Tombi, J. (2024). Some ecological aspects of Monogeneans (Platyhelminthes) ectoparasites of \u003cem\u003eEnteromius guirali\u003c/em\u003e Thominot, 1886 (Pisces: Cyprinidae) from Cesala River in Cameroon. \u003cem\u003eParasitology Research\u003c/em\u003e 123: 374. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s00436-024-08379-8\u003c/span\u003e\u003cspan address=\"10.1007/s00436-024-08379-8\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eŘehulkov\u0026aacute;, E., Seifertov\u0026aacute;, M., Francov\u0026aacute;, K. and Šimkov\u0026aacute;, A. (2023). Nearctic \u003cem\u003eDactylogyrus\u003c/em\u003e (Playhelminthes, Monogenea) parasitizing cypriniform fishes in the context of morphology and phylogeny, with descriptions of seven new species. \u003cem\u003eParasite\u003c/em\u003e 30 (30). \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1051/parasite/2023032\u003c/span\u003e\u003cspan address=\"10.1051/parasite/2023032\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eŠimkov\u0026aacute;, A., Desdevises, Y., Gelnar, M. and Morand, S. (2000). Co-existence of nine gill ectoparasites (Dactylogyrus: Monogenea) parasitising the roach (\u003cem\u003eRutilus rutilus\u003c/em\u003e L.): history and present ecology. \u003cem\u003eInternational Journal Parasitology\u003c/em\u003e 30(10):1077\u0026ndash;1088.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWong, W.L., Tan, W.B. and Lim, L.H.S. (2006). Sodium dodecyl sulphate as a rapid clearing agent for studying the hard parts of monogeneans and nematodes. \u003cem\u003eJournal of Helminthology.\u003c/em\u003e 80(1): 87\u0026ndash;90.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZharikova, T.I. (2000). The adaptive reactions of the gill ectoparasites of the bream (\u003cem\u003eAbramis brama\u003c/em\u003e) and of the white (\u003cem\u003eBlicca bjoerkna\u003c/em\u003e) to exposure to an anthropogenic factor in the Ivan\u0026rsquo;Kovo reservoir. \u003cem\u003eParasitologia\u003c/em\u003e 34(1): 50\u0026ndash;55.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZolovs, M. \u0026amp; Kirjušina, M. (2012). The attachment apparatus and copulatory organ morphometric differences between \u003cem\u003eDactylogyrus crucifer\u003c/em\u003e Wagener, 1857 (Monogenea: Dactylogyridae) from lake and river environments. \u003cem\u003eActa Biologica Universitatis Daugavpiliensis\u003c/em\u003e 12(1): 106\u0026ndash;112.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZolovs, M., Ozuna, A. and Kirjušina, M. (2012). Seasonal variation of attachment apparatus and copulatory organ morphometric variables of \u003cem\u003eDactylogyrus crucifer\u003c/em\u003e Wagener, 1857 (Monogenea: Dactylogyridae) on the gills of roach (\u003cem\u003eRutilus rutilus\u003c/em\u003e L.) in Latvian water bodies. \u003cem\u003eActa Biologica Universitatis Daugavpiliensis\u003c/em\u003e 12(2): 191\u0026ndash;198.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZolovs, M., Deksne, G., Daukste, J., Aizups, J. and Kirjušina, M. (2016). Morphometric analysis of the hard parts of \u003cem\u003ePseudodactylogyrus anguillae\u003c/em\u003e and \u003cem\u003ePseudodactylogyrus bini\u003c/em\u003e (Monogenea: Dactylogyridae) on the gill apparatus of the European eels (\u003cem\u003eAnguilla anguilla\u003c/em\u003e) from the fresh waters of Latvia. \u003cem\u003eThe Journal of Parasitology\u003c/em\u003e 102(3): 388\u0026ndash;394.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"systematic-parasitology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"","sideBox":"Learn more about [Systematic Parasitology](https://www.springer.com/journal/11230)","snPcode":"11230","submissionUrl":"https://submission.nature.com/new-submission/11230/3","title":"Systematic Parasitology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Cameroon, freshwater, Teleost, Monogenea, morphology, taxonomy","lastPublishedDoi":"10.21203/rs.3.rs-8595830/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8595830/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eMonogeneans are fish ectoparasites which infested commonly gill filament. They are characterised by their sclerotized haptoral and genital structures. Morphological study of gill monogeneans was conducted at Lebamzip, Center Region of Cameroon. Fish were caught along Cesala River using fishing rods or gillnets, kept in icebox and transported to the laboratory of parasitology and ecology at University of Yaound\u0026eacute; I. Each monogenean was mounted between slide and coverslip in a drop of GAP mixture. Drawings of the sclerotized structures were made using Corel Draw and measurements were taken on Amscope. Four monogeneans species belonging to the genus \u003cem\u003eDactylogyrus\u003c/em\u003e were inventoried. One new species is described (\u003cem\u003eD. cesalaensis\u003c/em\u003e n. sp. from \u003cem\u003eE. aspilus\u003c/em\u003e) and three described species as follows: \u003cem\u003eD. aspili\u003c/em\u003e from \u003cem\u003eE. aspilus\u003c/em\u003e; \u003cem\u003eD. mendehei\u003c/em\u003e and \u003cem\u003eD. nyongensis\u003c/em\u003e from \u003cem\u003eE. guirali\u003c/em\u003e are rediscribed. Each monogenean species presented a filamentous anchor and MCO with a flame type accessory piece. Particularly, \u003cem\u003eD. cesalaensis\u003c/em\u003e n. sp. have dorsal bar W-shaped; filamentous hooks; vagina shaped like a dagger blade. For \u003cem\u003eD. aspilus\u003c/em\u003e: dorsal bar V-shaped; pair I of hooks most developed without filament; pairs II-VII are filamentous; vagina is a leaf-like piece with spiny ends. Concerning \u003cem\u003eD. mendehei\u003c/em\u003e: pair I of hooks without filament; pairs II-VII are filamentous; dorsal bar U-shaped. For \u003cem\u003eD. nyongensis\u003c/em\u003e: dorsal bar arched; filamentous hooks; three forms of MCO belonging to the flame type observed; vagina comma-shaped. All encountered monogeneans are classed in the \u003cem\u003eDactylogyrus wunderi\u003c/em\u003e type. Colonisation-extinction phenomena explained the parasitic richness observed during this study.\u003c/p\u003e","manuscriptTitle":"Morphological characterisation of gill monogeneans (Monogenea: Dactylogyridae) of Enteromius aspilus Boulenger, 1907 and Enteromius guirali Thominot,1886 captured in the Cesala River, Cameroon ","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-01-22 08:42:17","doi":"10.21203/rs.3.rs-8595830/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-03-10T18:21:39+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-03-10T12:31:48+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-02-08T03:12:23+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"137742584445290111775925053302701285195","date":"2026-02-08T01:15:01+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"231426172601098045548029242581489663270","date":"2026-01-28T20:38:48+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-01-20T21:33:41+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-01-16T07:44:53+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-01-16T07:42:11+00:00","index":"","fulltext":""},{"type":"submitted","content":"Systematic Parasitology","date":"2026-01-13T22:02:54+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"systematic-parasitology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"","sideBox":"Learn more about [Systematic Parasitology](https://www.springer.com/journal/11230)","snPcode":"11230","submissionUrl":"https://submission.nature.com/new-submission/11230/3","title":"Systematic Parasitology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"daa67b02-7f05-49c0-8820-62298c189822","owner":[],"postedDate":"January 22nd, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-03-26T20:24:22+00:00","versionOfRecord":[],"versionCreatedAt":"2026-01-22 08:42:17","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8595830","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8595830","identity":"rs-8595830","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}