Integrative taxonomy of Annulotrema (Monogenea: Dactylogyridae) from some Characiformes of Cameroon: Redescriptions and morphogroup delimitation using numerical phylogeny

Integrative taxonomy of Annulotrema (Monogenea: Dactylogyridae) from some Characiformes of Cameroon: Redescriptions and morphogroup delimitation using numerical phylogeny | 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 Integrative taxonomy of Annulotrema (Monogenea: Dactylogyridae) from some Characiformes of Cameroon: Redescriptions and morphogroup delimitation using numerical phylogeny TOMBI Jeannette, Ivan NDONGO, Michel Thierry ONANA NGONO, AKOUMBA John Francis, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7468163/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 7 You are reading this latest preprint version Abstract The study of the monogenean fauna of four Characiformes consumed in Cameroon has allowed the redescription of seven species of Annulotrema Paperna and Thurston, 1969 and has provided new information for the diagnosis of these helminths. Thus, concerning the parasites of Brycinus kingsleyae Günther, 1986, in Annulotrema combesi Birgi, 1988, the copulatory tube can make two turns of spire contrary to the initial description which indicates a single turn; on the dorsal transverse bar of Anulotrema maillardi Birgi, 1988, a sclerotized structure was observed for the first time; a loop was also noted for the first time on the ventral bar of Annulotrema nyongesnsis Birgi, 1988. For parasites of Phenacogrammus major , the vagina was observed for the first time in Annulotrema gabrioni Birgi, 1988. A membrane extension never reported on the dorsal transverse bar of Annulotrema hepseti Paperna and Thurston, 1969, a parasite of Hepsetus odoe was observed during this study. Numerical phylogeny allowed the assignment of a morphogroup to the two newly described species in Brycinus macrolepidotus Valenciennes, 1849. Thus, a new morphologroup named Ngombiensis n. gr. was created to classify Annulotrema ngombiensis Ndongo and Tombi, 2023. As for Annulotrema nkengfacki Ndongo and Tombi, 2023, its morphometric characteristics allow it to be associated with the Nyongensis group created by Birgi in 1988. Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 1- Introduction The order of Characiformes includes 3 families, 20 genera and about 53 species of fish, the majority of which belong to the Alestidae family (Stiassny, 2007). These fish are widely consumed in Africa. In addition to their flavour, the interest of populations in these freshwater teleost also lies in their movement in schools which facilitates their capture (Brummet, 1988). The enormous losses recorded by fish farmers wishing to cultivate some Characidae such as Brycinus macrolepidotus Valenciennes, 1849 have contributed to the non-existence of Characiform fish production policies in some African countries, notably Cameroon (Ndongo, 2025 ). Gill monogeneans are to some extent responsible for the massive losses recorded in aquaculture, so it would be essential to conduct a study of this group of parasites before embarking on a fish farming project (Bilong Bilong, 1995 ; Buchmann & Lindenstrom, 2002 ). Characidea are host monogeneans of the genera Afrocleidodiscus (1 species), Characidotrema (11 species) and Annulotrema (57 species) (Řehulková et al., 2019 ; Kičinjaová et al., 2024 ). Note that only the last two genera have already been recorded in Cameroon. Until 2023, the only available data on monogeneans of Characiformes in Cameroon came from Birgi ( 1988 ) which allowed the description of 17 species of Annulotrema and the establishment of five morphogroups. It is only very recently that Ndongo et al. ( 2023 ) discovered two Annulotrema which exploit B. macrolepidotus in the Nyong River. Proving that this group of parasites remains very little known in our country. The present work is therefore the continuation of the study carried out by Ndongo et al. ( 2023 ) and aims to revisit the diagnosis of certain Annulotrema from Cameroon and to highlight their morphometric links. 2- Materials and methods 2-1- Fish sampling From February 2019 to December 2020, fish catches were made by local fishermen using nets of varying mesh sizes (1cm x 1cm, 2.5 cm x 2.5) in the lowersins of the Dibamba and Nyong on its main course in Akonolinga, and in the Mefou and Akono rivers in Yaoundé (respectively in the villages of Afanoyoa and Binguéla) (Fig. 1 ). These fishes were kept in the icebox with ice inside. 2-2- Parasitological analysis and morphological characterisation After the dissection of fish, each gill were removed and isolated in Petri dishes containing tap water. Then, each monogenean was dislodged from the gill with fine needle and mounted between slide and coverslip (in situ or in the laboratory located at the University of Yaoundé I). Each monogenean was mounted in a drop of mixture of glycerine and ammonium picrate and the slides were sealed 72 hours later with glyceel (Malmberg, 1957 ; Bates, 1997 ). The microphotographs of the different sclerotized parts of the haptor and the genital apparatus were taken with the Amscope MU 408 microphotography device connected to a computer and the YVYMEN optical microscope. These photographs were subsequently analysed using Amscope and Corel Draw X8 software respectively to determine the measurements of the different sclerotized pieces and to produce drawings of the latter. The different measurements and nomenclatures were made respectively according to Ndongo et al. ( 2023 ) and ICOPA IV (Euzet and Prost, 1981 ). The different measurements are presented in micrometres according to the mean ± standard deviation (minimum-maximum) model (when n ≥ 10 individuals). The paratypes were kept at the National Museum of Natural History in Paris (MNHN). 2-3- multivariate analysis To visualise the morphological links between the species, a principal component analysis (PCA) was performed using SPSS software v26.0. The analyses included 23 measurements from the haptorial pieces and the male copulatory organ (MCO). Each measurements was converted into ratio by dividing its value by that of the hook II (as its size varies little with the size of the animal). The body length of the animal was not considered. The species and the variables of the sclerotized parts considered for this study are respectively listed in Table 1 and Table 2 . Table 1 Variables used to establish morphometric links between Annulotrema species recorded in Cameroon 1 MCO Total length Hooks H 2 I Total length 3 III Total length 4 IV Total length 5 V Total length 6 VI Total length 7 VII Total length Ventral bar VB 8 VBL Total length 9 VBW Total width 10 VBMW Median width Dorsal bar DB 11 DBL Total length 12 DBW Total width 13 DBMW Median width Ventral anchor VA 14 VAI Inner length 15 VAE Outer length 16 VAIR Inner root length 17 VAOR Outer root length 18 VAP Point length Dorsal anchor DA 19 DAI Inner length 20 DAO Outer length 21 DAIR Inner root length 22 DAOR Outer root length 23 DAP Point length Table 2 List of Annulotrema species (with type-host and locality) from Cameroun whose sclerotized parts measurements were used for the PCA with their respective morphogroups established by Birgi, 1988 Species Host Locality Authority Morphogroup A. combesi Brycinus kingsleyae Günther,1986 Ebogo: Nyong River Birgi, 1988 Combesi A. nyongensis Brycinus kingsleyae Günther,1986 Ebogo: Nyong River Birgi, 1988 Nyongensis A. gabrioni Phenacogrammus major Boulenger, 1903 et Hemigrammopetersius pulcher Boulenger, 1909 Sangmelima: Dja River Yaoundé: Nyong River Birgi, 1988 A. amieti* Phenacogrammus major Boulenger, 1903 et Hemigrammopetersius pulcher Boulenger, 1909 Sangmelima: Dja River Yaoundé: Nyong River Birgi, 1988 Amieti A. bouixi Brycinus kingsleyae Günther, 1986 Ebogo: Nyong River Birgi, 1988 A. edeensis* Micralestes sp Somakek: Sanaga River Birgi, 1988 A. kribiensis* Brycinus longipinnis Günther, 1864 Moanko: Sanaga River Birgi, 1988 A. lamberti* Brycinus longipinnis Günther, 1864 Moanko: Sanaga River Birgi, 1988 A. maillardi Brycinus kingsleyae Günther,1986 Ebogo: Nyong River Birgi, 1988 A. moanko* Brycinus longipinnis Günther, 1864 Moanko: Sanaga River Birgi, 1988 A. sangmelinensis* Micralestes humilis Boulenger, 1899 Sangmelima: Dja River Birgi, 1988 A. nannoethiopis* Nannoethiopis unitoeniatus Günther, 1872 Nkolya: Nyong River Birgi, 1988 Nannoethiopis A. bilongi* Neolebias trewavasae Poll et Goss, 1963 Nkolya: Nyong River Birgi, 1988 A. endjami* Neolebias trewavasae Poll et Goss, 1963 Nkolya: Nyong River Birgi, 1988 A. fomenai* Neolebias trewavasae Poll et Goss, 1963 Nkolya: Nyong River Birgi, 1988 A. hepseti Hepsetus odoe Block, 1794 Nyong River Paperna and Thurston, 1969 Hepseti A. ngombiensis** Brycinus macrolepidotus Valenciennes, 1849 Akonolinga: Nyong River Ndongo and Tombi, 2023 ??? A. nkengfacki** Brycinus macrolepidotus Valenciennes, 1849 Akonolinga: Nyong River Ndongo and Tombi, 2023 ??? ??? : The morphogroup of this species will be determined after the analysis; *: sclerotized parts measurements obtained from Birgi ( 1988 ); **: sclerotized parts measurements obtained from Ndongo et al. ( 2023 ) 3- Results 3-1- Morphological description Annulotrema combesi Birgi, 1988 Type host : Brycinus kingsleyae Günther, 1896 Type locality: Nyong River in Ebogo, Cameroon Other localities: Nyong Cameroun Melan (3°46' 11.424''N; 12°16' 22.236''E), Sombo (3°46' 13.548''N; 12°16' 27.612''E) Infestation site: Gills Prevalence: 5% (2 parasitized fish out of 40 fish examined) Number of individuals studied: 2 mounted in Malmberg liquid Type specimen: Paratype MNHN HEL 2076 Redescription ( Fig. 2 ) Total length = 454–455; pharyngeal width = 104; ovary width = 131–133. Haptor width = 98–99. Ventral anchors without filaments, robust, arched with a reduced point. Inner length = 57–58; outer length = 58–59. Inner root length = 18; outer root length = 8–10 and point length = 2–3. Dorsal anchors filiform with a vestigial inner root, a long outer root and a reduced point. Inner length = 52–53; outer root length = 20–24 and point length = 1–3. Ventral bar with swollen ends. The anterior side forms an accolade. Total length = 23–24; Total width = 8–9, median width = 6 and diameter of the median loop = 3. Very thin dorsal bar forms a lying 7. Total length = 20–21; total width = 7 and median width = 2. Hooks with filament; pairs I to V more robust. Pair I = 9–10; pair II = 15–16; pair III = 27–28; pair IV = 25–27; pair V = 23–24; pair VI = 22–23; pair VII = 23–24. The male copulatory organ (MCO) begins with an oval basal bulb fused to an elongated accessory part. The copulatory tube makes two turns of the spire in the counter clockwise direction before sliding into the distal part of the accessory part. Total length = 28–29; tube trace length = 148–149; diameter of the first turn of the spire = 16–17; diameter of second turn of spire = 28–29; distance between turns of spire = 5; base length = 9 and base width = 6. The vagina was not observed. Remarks The description was made by Birgi ( 1988 ) in the same host in the Nyong River. Some characteristics observed during this redescription do not coincide with those presented during the original description. Indeed, the arrangement of the accessory part in relation to the copulatory tube does not correspond to that presented by Birgi ( 1988 ). Furthermore, for this author, the copulatory tube describes one turn of spire compared to two in the present study. In addition, the measurements of hooks I and II reported by Birgi ( 1988 ) are larger (50 and 20 µm respectively) compared to ours (9 and 15 µm respectively). We nevertheless believe that these differences are not sufficient to separate the present species from A. combesi . We prefer so for the moment to attach the specimens obtained to this species. Annulotrema maillardi Birgi, 1988 Type host : Brycinus kingsleyae Günther, 1986 Type locality: Nyong River in Ebogo, Cameroon Other localities: Nyong: Melan (3°46' 11.424''N; 12°16' 22.236''E), Sombo (3°46' 13.548''N; 12°16' 27.612''E), Nyong Bridge Cameroon (3°46' 10.53''N; 12°14' 49.062 E); Mefou River at Afanoyo'o (3°44' 60''N; 11°27' 51''E). Infestation site: Gills Prevalence: 20% (8 parasitized fish out of 40 examined) Number of individuals studied: 10 mounted in Malmberg liquid Type specimen: Paratype MNHN HEL2077 Redescription ( Fig. 3 ) Total length = 569 ± 46.38 (508–636); width at pharynx = 101 ± 8.81 (89–110) and width at ovaries = 148 ± 35.01 (102–177). Haptor width = 88 ± 27.34 (45–122). Robust ventral anchors with filament, reduced outer root and marked point. Inner length = 45 ± 1.7 (43–48); outer length = 41 ± 1.3 (39–43); inner root length = 15 ± 1.88 (14–18); outer root length = 5 ± 0.59 (4–6) and point length = 5 ± 0.75 (3–6). Thin, elongated dorsal anchors with filament, developed inner root and marked point. Inner length = 50 ± 3.21 (47–53); outer length = 35 ± 1.9 (33–38); inner root length = 24 ± 1.93 (21–27); outer root length = 7 ± 1.81 (5–10) and point length = 4 ± 0.84 (3–5). Ventral bar with swollen ends with a thin median part and membranous extension on the basal side. Total length = 25 ± 2.5 (22–27); total width = 16 ± 2.55 (13–19) and median width = 12 ± 2.47 (8–15). Triangular dorsal bar surmounted by a thin rectilinear structure. Total length = 23 ± 2 (20–26); total width = 12 ± 1.08 (11–14) and median width = 9 ± 0.74 (8–10). Dissimilar hooks, robust and without filament. Pair I = 20 ± 1.71 (17–22); pair II = 10 ± 0.89 (8–11); pair III = 23 ± 5.15 (17–34); pair IV = 27 ± 1.02 (26–29); pair V = 29 ± 1.13 (28–31); pair VI = 25 ± 1.17 (25–28); pair VII = 22 ± 2.31 (19–26). The MCO begins with an oval basal ampulla. Penis rotates counter clockwise, a thin, flat accessory part fused to the basal ampulla. Total length = 21 ± 0.99 (20–22); tube trace length = 49 ± 1.15 (48–51); base length = 6 ± 0.72 (5–7) and base width = 4 ± 0.48 (3–5). The vagina was not observed. Remarks The morphology of the MCO of the parasite redescribed in this paper is reminiscent of that of Annulotrema maillardi Birgi, 1988 collected from the gills of the same host species in the Nyong River at Ebogo in Cameroon. However, the specimens observed during the current study show some differences compared to the original description of this species. Indeed, the ventral bar described by Birgi is a simple convex quadrilateral while the specimens in the present study have a flattened dorsal bar with a mid-basal extension. In addition, in Birgi ( 1988 ) the dorsal bar is a quadrilateral with narrowed edges while in our specimens, this bar is triangular and surmounted by a median sclerotized piece. Given that the morphology of the genital parts corresponds to that of A. maillardi , we assign the specimens studied to this species. Annulotrema bouixi Birgi, 1988 Type host : Brycinus kingsleyae Günther, 1986 Type locality: Nyong River in Ebogo, Cameroon Other localities: Nyong at Melan (3°46' 11.424''N ; 12°16' 22.236''E), Sombo (3°46' 13.548''N ; 12°16' 27.612''E), Pont (3°46' 10.53''N ; 12°14' 49.062 E); Mefou River at Afanoyo'o (3°44' 60''N ; 11°27' 51''E) Infestation site: Gills Prevalence: 75% (30 parasitized fish out of 40 fish examined) Number of individuals examined: 10 mounted in Malmberg liquid Type specimen: Paratype MNHN HEL2078 Redescription ( Fig. 4 ) Body length 423 ± 49.99 (370–489); width of pharynx 63 ± 14.84 (44–93); width at ovaries 82 ± 11.43 (61–100) and width of haptor 80 ± 13.43 (52–95). Robust ventral anchors with filaments and with well-individualized inner root and outer root. Arched blade and reduced point. Inner length = 28 ± 2.26 (24–29); outer length = 31 ± 2.15 (28–30); inner root length = 10 ± 1.49 (9–13); outer root length = 7 ± 1.71 (4–9); point length = 3 ± 0.36 (3–4). Dorsal anchors swollen at the inner root-outer root connection with filament and marked point. Inner length = 34 ± 2.11 (31–37); outer length = 27 ± 2.63 (26–29); inner root length = 13 ± 1.70 (12–15); outer root length = 4 ± 1.58 (3–8); point length = 3 ± 0.44 (3–4). Rectangular ventral bar, forms a thick, slightly curved blade with a mid-basal part connected by a thin longitudinal sclerotization to another, less thick, parallel blade (reminiscent of the shape of an inverted T). Total length = 21 ± 2.54 (18–27); total width = 11 ± 1.57 (11–13); median width = 9 ± 0.88 (7–10); T-bar length = 12 ± 2.77 (8–13). Y-shaped dorsal bar. Total length = 21 ± 2.12 (18–23); total width = 14 ± 1.80 (11–17); median width = 9 ± 1.38 (8–11). Dissimilar hooks with filaments on pairs III to VII. Pair I = 16 ± 1.28 (14–18); pair II = 9 ± 0.89 (8–10); pair III = 21 ± 1.98 (20–24); pair IV = 22 ± 2.13 (19–25); pair V = 25 ± 3.6 (19–27); pair VI = 21 ± 2.43 (16–23); pair VII = 18 ± 2.9 (13–23). The MCO with oval basal bulb fused to the basal part of the accessory piece, describes a clockwise loop. Total length = 20 ± 2.03 (18–25); tube trace length = 46 ± 5.10 (40–55); base length = 4 ± 0.35 (3–4) and base width = 4 ± 0.73 (3–4). The vagina is tubular and pediform with Length = 26. Remarks The size of the specimens collected during this study, the morphology and the measurements of the different sclerotized parts of the haptor and the copulatory apparatus correspond to those of Annulotrema bouixi Birgi, 1988 described on the gills of B. kingsleyae captured in the Nyong River in the village of Ebogo. The only difference lies in the lower blade of the ventral bar, the size of which is larger than that mentioned in the original description (8–12 vs 4). This minimal difference allows us to link the present specimens to those of the species Annulotrema bouixi . Annulotrema nyongensis Birgi, 1988 Type host : Brycinus kingsleyae Günther, 1986 Type locality: Nyong River in Ebogo, Cameroon Other localities: Nyong at Melan (3°46' 11.424''N ; 12°16' 22.236''E), Sombo (3°46' 13.548''N ; 12°16' 27612''E), Pont (3°46' 10.53''N ; 12°14' 49.062 E); Mefou River at Afanoyo'o (3°44' 60''N ; 11°27' 51''E) Infestation site: Gills Prevalence: 25% (10 parasitized fish out of 40 fish examined) Number of individuals examined: 10 mounted in Malmberg liquid Type specimen: Paratype MNHN HEL 2079 Redescription ( Fig. 5 ) Body length = 355 ± 16.03 (338–379); width at the pharynx = 54 ± 6.58 (44–62); width at the ovaries = 76 ± 12.69 (58–93); haptor width = 67 ± 10.73 (48–89). Ventral anchors with inner root and outer root not very individual, much-arched blade and little marked point. Inner length = 21 ± 0.49 (20–22); outer length = 24 ± 0.52 (23–24); inner root length = 8 ± 0.49 (8–9); outer root length = 5 ± 0.92 (3–6); point length = 1 ± 0.18 (1–2). Dorsal anchors less robust than the ventral ones, inner root and outer root well individualized. Thin blade with reduced point. Inner length = 24 ± 0.62 (23–25); outer length = 22 ± 0.38 (21–23); inner root length = 8 ± 0.41 (8–9); outer root length = 4 ± 0.5 (4–5); point length = 1 ± 0.44 (1–2). Thick and curved ventral bar with a median loop. Total length = 19 ± 1.05 (18–21); total width = 11 ± 2.06 (7–13); median width = 5 ± 1.03 (4–6); diameter of the loop = 2 ± 0.23 (1–2). Dorsal bar in the shape of A letter. Total length = 17 ± 0.65 (15–17); length of the large bar = 10 ± 0.91 (8–11); length of the small bar = 7 ± 4.95 (6–8); total width = 13 ± 2.81 (7–15); median width = 8 ± 1.71 (4–9). Sturdy hooks with filament. Pair I = 14 ± 1.39 (10–15); pair II = 12 ± 1.06 (11–14); pair III = 15 ± 1.88 (11–17); pair IV = 16 ± 0.59 (15–17); pair V = 18 ± 0.91 (17–19); pair VI = 17 ± 0.83 (15–17); pair VII = 17 ± 0.83 (16–18). The MCO with oval basal ampulla and copulatory tube which, after a slight undulation, slides between the two branches of the terminal part of the accessory piece. Total length = 35 ± 1.97 (32–40); tube trace length = 35 ± 3.13 (31–40); base length = 5 ± 0.31 (4–5); base width = 4 ± 0.25 (4–5). The vagina was not observed. Remarks The similarities observed in the sclerotized parts of the haptor and the male copulatory organ allow us to link the specimens of the present parasite to the species Annulotrema nyongensis Birgi, 1988 , an ectoparasite of B. kingsleyae . However, the measurements of the specimens obtained during the present study are smaller than those of the original description (355 vs 500). Furthermore, Birgi does not mention the loop observed at the level of the ventral transverse bar of all the specimens but a slight swelling. Annulotrema amieti Birgi, 1988 Type host : Phenacogrammus major Boulenger, 1903 Type locality: Nyong Basin in Yaoundé and Dja Basin in Sangmélima Other localities: Akono River in Binguéla (3°42' 8''N; 11°37' 57''E) Infestation site: Gills Prevalence: 80% (40 parasitized fish out of 50 fish examined) Number of individuals examined: 10 mounted in Malmberg liquid Type specimen: Paratype MNHN HEL 2081 Redescription ( Fig. 6 ) Body length 604 ± 207.33 (304–763); width at pharynx 58 ± 17.64 (36–79); width at ovaries 66 ± 17.13 (46–87) and haptor width 85 ± 19.79 (72–114). Ventral anchors with well-individualized inner root and outer root. The blade is arched and the point is developed. Inner length = 33 ± 1.40 (31–35); outer length = 32 ± 1.92 (30–35); inner root length = 11 ± 0.98 (9–13); outer root length = 7 ± 0.79 (6–9); point length = 4 ± 0.40 (3–4). Dorsal anchors with well-individualized inner root and thicker outer root in its basal part. Arched blade with long point. Inner length = 32 ± 3.0 (28–35); outer length = 32 ± 3.02 (26–35); inner root length = 10 ± 1.40 (9–13); outer root length = 6 ± 1.07 (5–8) and point length = 4 ± 0.72 (3–5). Ventral bar with median expansion that then divides into two obliquely curved branches to reach the base by means of fine filaments. Total length = 24 ± 2.30 (21–26), total width = 13 ± 2.59 (10–18); median width = 4 ± 0.76 (3–5). Triangular dorsal bar, concave and longer on the anterior side. Total length = 23 ± 2.0 (20–27); Total width = 11 ± 1.4 (9–13); median width = 7 ± 1.09 (4–8). The hooks are dissimilar with pairs III to VII provided with filaments. Pair I = 14 ± 0.99 (13–15); pair II = 12 ± 0.78 (11–14); pair III = 19 ± 2.3 (16–23); pair IV = 21 ± 2.26 (17–24); pair V = 25 ± 3.9 (17–29); pair VI = 19 ± 3.24 (14–25); pair VII = 22 ± 1.47 (19–24). The MCO with an oval basal ampulla and copulatory tube forms a clockwise turn, slides into the middle part of the accessory part and emerges towards its terminal part. Accessory part hook-shaped. Total length = 19 ± 2.33 (16–22); tube trace length = 56 ± 4.06 (49–61); base length = 6 ± 1.29 (4–7); base width = 5 ± 0.8 (4–7). The vagina tubular and thin. Total length = 37. Remarks The haptor armature and the morphology of the MCO of the specimens obtained during our work are closer of those of Annulotrema amieti Birgi, 1988 described in Cameroon on the gills of P. major . Despite some size differences observed at the level of the ventral hooks and transverse bars, the dimensions of the other sclerotized parts recorded by the two studies remain very similar. In addition, the presence of these parasites in the same host species leads us to associate them with the species Annulotrema amieti . Annulotrema gabrioni Birgi, 1988 Type host : Phenacogrammus major Boulenger, 1903 Type locality: Nyong Basin in Yaoundé and Dja Basin in Sangmélima Other localities: Akono River in Binguéla (3°42' 8''N; 11°37' 57''E) Infestation site: Gills Prevalence: 50% (25 parasitized fish out of 50 fish examined) Number of individuals examined: 10 mounted in Malmberg fluid Type specimen: Paratype MNHN HEL 2082 Redescription ( Fig. 7 ) Body length 373 ± 68.81 (302–519); width at pharynx 47 ± 16.07 (13–64); width at ovaries 64 ± 16.46 (28–85) and haptor width 63 ± 11.23 (50–87). Ventral anchors with robust inner root, well-arched blade and short point. Inner length = 23 ± 0.98 (22–25); outer length = 26 ± 0.78 (25–27); inner root length = 8 ± 1.04 (7–10); outer root length = 4 ± 1.64 (2–7); point length = 1 ± 0.35 (1–2). Dorsal anchors less robust than the ventral ones, with well-developed inner root and outer root. Thin, slightly arched blade and long point. Inner length = 26 ± 0.69 (26–27); outer length = 26 ± 1.6 (23–29); inner root length = 9 ± 1.37 (7–11); outer root length = 5 ± 1.29 (3–7); point length = 2 ± 0.59 (1–3). Arched ventral bar. Total length = 19 ± 1.6 (17–22); total width = 10 ± 0.95 (9–12); median width = 4 ± 0.93 (3–7). Dorsal bar with the appearance of the letter A. Total length = 16 ± 1.0 (15–19); total width = 16 ± 1.78 (12–19); median width = 6 ± 0.67 (5–7); opening diameter = 6 ± 0.67 (5–7). Dissimilar hooks. Pair I = 13 ± 1.33 (12–16); pair II = 11 ± 1.30 (9–14); pair III = 14 ± 0.80 (13–15); pair IV = 14 ± 1.58 (12–18); pair V = 18 ± 1.86 (13–19); pair VI = 15 ± 1.09 (13–17); pair VII = 15 ± 1.01 (14–16). The MCO begins with an oval basal bulb, fused to the base of the accessory part. The copulatory tube is short and insinuates itself into the accessory part and then comes out. The accessory part splits in its basal part to form a cap in the distal part. Total length = 19 ± 1.51 (16–21); tube trace length = 19 ± 1.61 (16–21); base length = 5 ± 0.67 (4–6); base width = 3 ± 0.43 (3–4). The vagina is 35 µm long. It begins with a flat, spatula-shaped base 4 µm long and 3 µm wide and continues with a tube 31 µm long. Remarks The structure and size of most of the parts of the haptor, as well as the morphology and measurements of the MCO of the specimens collected during the present work, lead us to assimilate them to Annulotrema gabrioni Birgi, 1988 . However, the triangular apophysis reported in the initial description on the ventral bar (Birgi, 1988 ), was not observed during the analysis of our samples. Furthermore, Birgi does not report the sclerotization of the vagina. There are also differences in measurements at the level of the ventral and dorsal anchors (22–25 vs 26–30 and 26–27 vs 30–32 respectively). Annulotrema hepseti Paperna and Thurston, 1969 Type host : Hepsetus odoe (Block, 1794) Type locality: Beira River in New Tafo (Ghana) Other localities: Bia River at Ayamé in Ivory Coast, Okavango River at Mohembo in Botswana, Dibamba River at Japoma in Cameroon (3°55' 31''N ; 9°40' 21''E) Infestation site: Gills Prevalence: 100% (15 parasitized fish out of 15 fish examined) Number of individuals examined: 10 mounted in Malmberg liquid Type specimen: Paratype MNHN HEL 2084 Redescription ( Fig. 8 ) Body length 749 ± 94.70 (549–860); width at pharynx 97 ± 18.91 (62–128); width at ovaries 152 ± 26.33 (107–182) and haptor width 136 ± 20.70 (109–169). Ventral anchors with thick inner root, oblique blade and short point. Inner length = 50 ± 3.97 (41–54); outer length = 47 ± 2.74 (40–50); inner root length = 20 ± 1.69 (17–24); outer root length = 7 ± 1.15 (5–9); point length = 4 ± 0.9 (3–6). Dorsal anchors with inner root three times longer than the outer root. Slightly arched blade and short point. Inner length = 50 ± 3.67 (41–53); outer length = 41 ± 2.91 (34–45); inner root length = 19 ± 2.26 (17–24); outer root length = 7 ± 0.91 (5–8); point length = 4 ± 0.68 (3–5). Crescent-shaped ventral bar. Total length = 34 ± 4.01 (28–43); total width = 11 ± 2.51 (7–15); median width = 7 ± 1.26 (5–8). Dorsal bar with crescent-shaped base, surmounted by a median rectangular sclerotization. Total length = 28 ± 2.55 (24–32); Total width = 11 ± 1.75 (7–12); Median width = 7 ± 1.67 (5–10). Dissimilar hooks. Pair I = 29 ± 4.40 (18–33); Pair II = 13 ± 1.92 (7–14); Pair III = 36 ± 6.18 (20–43); Pair IV = 39 ± 9.30 (18–47); Pair V = 37 ± 6.09 (23–45); Pair VI = 35 ± 6.98 (18–41); Pair VII = 33 ± 5.12 (19–37). The MCO is elongated with a pear-shaped basal ampulla. Copulatory tube with twists, distal accessory part forms a small capsule that covers the terminal part of the copulatory tube. Total length = 65 ± 7.91 (52–76); tube trace length = 56 ± 7.80 (40–66); base length = 8 ± 2.09 (6–12); base width = 5 ± 0.6 (4–6). The vagina is tubular ending in a fork. Total length = 28 ± 3.51 (24–32). Remarks The morphology of the MCO is reminiscent of that of Annulotrema hepseti Paperna and Thurston, 1969, described in Ghana on the gills of H. odoe . A redescription of this flatworm on the same host species was made in Côte d'Ivoire (N'Douba et al ., 1997) and Botswana (Christison, 1998 ). Neither of these authors observed the membrane extension that we noted above the dorsal transverse bar. In addition, some measurements of the sclerotized parts of the haptor and copulatory apparatus obtained during the present study do not approach those of our predecessors. However, the great similarity observed in the morphology of the MCO and hooks allows us to link the samples examined to A. hepseti . 3-2- Numerical phylogeny The first of two principal component axes contributed respectively to 57.80% and 10.62% of the variation. Figure 9 shows a graphical representation of the two first component coefficients for each variable. The principal component 1 was largely influenced by the measurements of hooks, VAI, VAO, VAIR, VAOR, DAI, DAO, DAIR, DAOR, VBW, DBH, whereas component 2 was mostly influenced by VAP and DAP. The projection of the individuals onto the factorial axes (Fig. 10 ) reveals that A. nkengfacki is closer to the species of the Nyongensis group (red rectangle) with which it shares the same configuration of the MCO and bars. Specimen belonging to species A. ngombiensis are highly divergent from all other species described in Cameroon (black rectangle), thus suggesting the creation of a new morphogroup that we propose to name Ngombiensis n. gr. A great variability of the specimens of A. maillardi is highlighted, which may explain the morphological differences observed with the original morpho-description of Birgi ( 1988 ). The morphometric characters from the specimens of A. combesi seem to bring it closer to the species of the Nyongensis morphogroup ( A. gabrioni and A. nyongensis ). A significant scattering is also detected among the individuals of A. hepseti . The affinities between A. bouixi , A. amieti and A. maillardi . However, A. maillardi and A. bouixi have more affinities with A. hepseti , which is not the case of A. amieti (the circle). 4- Discussion This work highlights new criteria for the diagnosis of some Annulotrema from Cameroon. The large discrepancies observed between the descriptions of Birgi ( 1988 ) and our redescriptions on A. maillardi and A. combesi could have several origins according to the literature. First, the difference in the quality of the samples as stipulated by Kičinjaová et al. ( 2015 ) during the redescription of Annulotrema elongata Paperna and Thurston, 1969. Also, we have the mounting techniques used which would influence the visibility of certain parts to the detriment of others (Řehulková et al., 2014 ), thus explaining the differences in the representations of certain pieces and the non-observation of other ones. This last argument, cannot however be valid in our case because the preparations were made in both studies following similar protocols. We then side with Bilong Bilong ( 1995 ) and suggest the existence of morphological variability in time and space occupied by the host in monogeneans resulting from the influence of certain biotic and abiotic factors such as host size, climate or water quality. Numerical phylogeny was used for the first time to group Annulotrema . It thus confirmed some of the observations from the morphological studies made by Birgi ( 1988 ); firstly by supporting the criteria for creating the different morphogroups of Annulotrema in Cameroon, and also by stipulating the need to create a new morphogroup to classify A. ngombiensis . Indeed, this species has an MCO whose configuration is far from all those listed on Annulotrema in Cameroon but this configuration of the MCO is rather close to that of Annulotrema parasitizing fishes of the genus Hydrocynus of West and East Africa. Multivariate analysis are however widely used to make affiliations among monogeneans of the same genus. This is for example the case of Bahanak et al. ( 2022 ) on monogeneans of the genus Quadriacanthus in Cameroon. Indeed, these authors used a PCA analysis to confirm that the morphometric parameters used for the description of Quadriacantus barombiensis Bahanak, Nack and Pariselle, 2022 parasitic of Clarias maclareni Trewavas, 1962 were sufficient to separate this monogenean from its other congeners of Lake Barombi Mbo. Bahanak ( 2018 ) used a similar approach to create three groups within the fish-parasitic monogeneans of the genus Quadriacanthus in the family Clariidae, to confirm morphological observations made on the anchors and cunei of these monogeneans. Other authors have also used PCA to identify relationships between several species of monogeneans belonging to the same genus (Mariniello et al., 2003; Sarabeev and Balbuena, 2004 ; Rubtsova et al., 2006 ; Mulega et al., 2022 ). 5- Conclusion This work shows that the data collected during the work of Birgi ( 1988 ) are sometimes very far from the current ones. Hence the need to provide new type slides to facilitate diagnoses. The morphological analyses retained are sufficient to discriminate the species of monogeneans of the genus Annulotrema . However, the distance of the individuals of certain species revealed during the PCA analysis could suggest a genetic separation (or a speciation phenomenon) verifiable with molecular tools. However, the almost non-existence of molecular data on the monogeneans of the genus Annulotrema shows that only numerical phylogeny allows today to study the links between this group of monogeneans especially with regard to less developed countries. Statements and declarations Competing of interests: The authors declare that they have no conflict of interest. Ethical approval: All procedures involving animals were permitted and were strictly according to the rules of the committee for Animal and Human Bioethics (Ethical clearance Reference N°: BTC-JIRB2022-026) Acknowledgements: We thank the Professor Jean-Lou Justine of the National Museum of Natural History of Paris for his help in the conservation of type specimens. Fund : No funding was received for the completion of this project. Author contributions All authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by NDONGO Ivan, TOMBI Jeannette, ONANA NGONO Michel Thierry, AKOUMBA John Francis and FOMENA Abraham. The first draft of the manuscript was made by NDONGO Ivan and all authors read and approved the final manuscript. References Bahanak, D. N. D. (2018). Systématique, phylogénie, biogéographie et origine des Monogènes parasites des Clariidae du Cameroun . Thèse Université de Yaoundé I, 187p. Bahanak, D.N.D., Nack, J., Mbondo, J.A., Bassock Bayiha, E.D., Pariselle, A., Bilong Bilong, C.F. & Agnèse, J.F. (2022). Description of a new species from Clarias maclareni and phylogenetical analysis of Quadriacanthus (Monogenea, Dactylogyridae) species transfers between clariid and non-clariid fish hosts in Cameroon. Parasite , 29 (37), 1-12. https://doi.org/10.1051/parasite/2022035 Bates, J.W. (1997). The slide-sealing compound “Glyceel”. Journal of Nematolology , 29 , 565-566. 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’Etat, Université de Yaoundé I, 341p. Birgi, E. (1988). Les monogènes de Characoidea de la zone forestière Camerounaise. Annales de la Faculté des Sciences Biologique et Biochimique , 3 (5), 59-111. Brummett, R. E., Nguenga, D., Tiotsop, F. & Abina, J.C. (2010).The commercial fishery of the midle Nyong River, Cameroon productivity and environmental threats. Smithiana Bulletin , 11 , 3-16. Buchmann, K. & Lindenstrom, T. (2002). Interactions between monogenean parasites and their fish hosts. International Journal for Parasitology , 32 , 309-319. https://doi.org/10.1016/S0020-7519(01)00332-0 Christison, K.W. (1998). Branchial monogenean parasites (Monogenea: Dactylogyridae) of characin fishes from the Okavango river and Delta, Botswana . Thesis (M. Sc.) University of the Orange Free State, 251p. Euzet, L. & Prost, M. (1981). Report of the meeting on Monogenea: Systematics, biology and ecology. In: Slusarski (Ed.), Review of advances in parasitology Warsawa PWN. Polish Scientific Publishers , 1p. Kičinjaová, M.L., Blažek, R., Gelnar, M. & Řehulková, E. (2015). Annulotrema (Monogenea: Dactylogyridae) from the gills of African tetras (Characiformes: Alestidae) in Lake Turkana, Kenya, with descriptions of four new species and a redescription of A. elongata Paperna and Thurston, 1969. Parasitology Research , 114 , 4107-4120. https://doi.org/10.1007/s00436-015-4682-x Kičinjaová, M.L., Přikrylová, I., Seifertová, M., Řehulková, E., Gelnar, M & Smit, N. J. (2024). Annulotrema species (Monopisthocotylea, Dactylogyridae) parasiting African tetras (Characiformes, Alestidae) in the Phongolo River, South Africa with the description of four new species. Parasite, 31 (67), 1-14. http://doi.org/10.1051/parasite/2024066 Malmberg, G. (1957). On the occurrence of Gyrodactylus on Swedish fishes. Skrifterutgitiva av Södra Sveriges Fiskeriförening , (1956), 19-76. Marinello, L., Ortis, M., D’Amelio, S. & Petrarca, V. (2004). Morphometric variability between and within species of Ligophorus Euzet &Suriano, 1977 (Monogenea: Ancyrocephalidae) in the Mediterranean Sea. Systematic Parasitology , 57 , 183-190. https://doi.org/10.1023/B:SYPA.0000019080.43784.06 Mulega, M. F., Bukinga, F.M., Akoumba, J.F., Mulungula, P.M. & Pariselle, A. (2022). Monogeneans from Catfishes in Lake Tanganyika. I: Two new species of Bagrobdella (Dactylogyridae) from Auchenoglanis occidentatlis (Siluriformes: Claroteidae). Zoologia , (39), 13p. https://doi.org./10.1590/s1984-4689.v39.e22016 Ndongo, I. (2025). Faunistique et bio-écologie des monogènes branchiaux de quatre Characiformes (Poissons- Téléostéens) dans les régions du Centre et du Littoral, Cameroun . Thèse de Doctorat/PhD, Université de Yaoundé I. 185p. Ndongo, I., Akoumba, J.F., Tombi, J., Morand, S. & Fomena, A. (2023). Two new species of Annulotrema (Monogenea: Dactylogyridae) gill parasites of Brycinus macrolepidotus Valenciennes, 1849 from Nyong River, Cameroon. Acta Parasitologica , (68), 257-265. https://doi.org/10.1007/s11686-022-00645-y Řehulková, E., Kičinjaová, M.L., Mahmoud, Z.N., Gelnar, M. & Seifertová, M. (2019).Species of Characidotrema Paperna & Thurston 1968 (Monogenea: Dactylogyridae) from fishes of the Alestidae (Characiformes) in Africa: new species, host-parasite associations and first insights into the phylogeny of the genus. Parasite & Vectors , 12 (1), 1-21. https://doi.org/10.1186/s13071-019-3580-y Řehulková, E., Musilová, N. & Gelnar, M. (2014). Annulotrema (Monogenea: Dactylogyridae) from Hydrocynus brevis (Characiformes: Alestidae) in Senegal, with descriptions of two new species and remarks on Annulotrema pikei . Parasitology Research , 113 (9), 3273 ̶ 3280. https://doi.org/10.10007/s00436-014-3990-x Rubtsova, N.Y., Balbuena, J.A., Sarabeev, V.L., Blanco-Costa, I. & Euzet, L. (2006). Description and Morphometrical variability of a new species of Ligophorus and Ligophorus chabaudi (Monogenea: Dactylogyridae) on Mugil cephalus (Teleostei) from the Mediterranean Basin. Journal for Parasitology , 92 (3), 486-495. https://doi.org/10.16145/GE-747R.1 Sarabeev, V.L. & Balbuena, J.A (2004). Ligophorus pilengas n. sp. (Monogenea: Ancyrocephalidae) from the introduced So-iuy Mullet, Mugil soiuy (Teleostei:Mugilidae), in the Sea of Azov and Black Sea. Journal of Parasitology , 90 (2), 222-228. https://doi.org/10.1645/GE-163R Stiassny, M. L. J., Teugels, G. G. & Hopkins, C. D. (2007). Poissons d’eaux douces et saumâtres de basse Guinée, ouest de l’Afrique Centrale . Volume 1. Tervuren, Belgique. MRHC. IRD, Paris France Faune tropicale (42), 352-353. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 12 Dec, 2025 Reviews received at journal 23 Oct, 2025 Reviewers agreed at journal 20 Sep, 2025 Reviewers invited by journal 02 Sep, 2025 Editor assigned by journal 27 Aug, 2025 Submission checks completed at journal 27 Aug, 2025 First submitted to journal 27 Aug, 2025 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. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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-7468163","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":509051494,"identity":"01811f08-fbf5-4318-bb4e-936dbb0ba07b","order_by":0,"name":"TOMBI Jeannette","email":"","orcid":"","institution":"University of Yaoundé I","correspondingAuthor":false,"prefix":"","firstName":"TOMBI","middleName":"","lastName":"Jeannette","suffix":""},{"id":509051495,"identity":"61229cdf-8733-4c05-afe2-54b3380ee8c0","order_by":1,"name":"Ivan NDONGO","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA6UlEQVRIiWNgGAWjYBACNgTJfMDgA4jNTrwWtoTCGSCKmXi7eAw+84BtI6CYTyL52eOCMps8efcew802v7bJ8zEzMH74mIPHfIk0c+MZ59KKDc8cKzbO7btt2MbMwCw5cxseLTwHzKR52w4nbpyRvM04t+c2I1ALGzMvXi3Hv0G1JJj/tuy5bU9YC3sPxJb5EikGxgw/bicSo6VMmudcWuIGnmMJhr0Nt5PbmBmb8fpFvpl9mzRPmU3i/PbmAwY//ty2BTIOfviIRwscGBwAEoxtICZjAxHqQdaB1f0hTvEoGAWjYBSMLAAAYT9M2cpUjRUAAAAASUVORK5CYII=","orcid":"","institution":"University of Yaoundé I","correspondingAuthor":true,"prefix":"","firstName":"Ivan","middleName":"","lastName":"NDONGO","suffix":""},{"id":509051496,"identity":"fae625f0-87da-45b1-86f3-e53da4d5134d","order_by":2,"name":"Michel Thierry ONANA NGONO","email":"","orcid":"","institution":"University of Yaoundé I","correspondingAuthor":false,"prefix":"","firstName":"Michel","middleName":"Thierry ONANA","lastName":"NGONO","suffix":""},{"id":509051497,"identity":"208b6a99-405a-4d47-8872-d76f0d85f9a4","order_by":3,"name":"AKOUMBA John Francis","email":"","orcid":"","institution":"University of Yaoundé I","correspondingAuthor":false,"prefix":"","firstName":"AKOUMBA","middleName":"John","lastName":"Francis","suffix":""},{"id":509051498,"identity":"f632e4e7-2891-4a43-aa83-e2436153cca3","order_by":4,"name":"FOMENA Abraham","email":"","orcid":"","institution":"University of Yaoundé I","correspondingAuthor":false,"prefix":"","firstName":"FOMENA","middleName":"","lastName":"Abraham","suffix":""}],"badges":[],"createdAt":"2025-08-27 06:08:04","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7468163/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7468163/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":90798189,"identity":"d5fb4d42-99b9-4e3c-9f5c-a8040033d151","added_by":"auto","created_at":"2025-09-08 09:37:13","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":135676,"visible":true,"origin":"","legend":"\u003cp\u003eMap of localisation of the sampling localities of the fish hosts examined\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-7468163/v1/2e4c4aefe6c2359a01050170.png"},{"id":90798190,"identity":"f0a10b34-2f30-45e8-b230-a3025ad16099","added_by":"auto","created_at":"2025-09-08 09:37:13","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":114041,"visible":true,"origin":"","legend":"\u003cp\u003eDrawings of sclerotized parts of \u003cem\u003eA. combesi\u003c/em\u003e, Va = ventral anchor; Da = dorsal anchor; VB = ventral bar; DB = dorsal bar; HI-HVII = hooks (pairs I-VII); MCO = male copulatory organ\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-7468163/v1/22a665ee0a9e366a9958b643.png"},{"id":90798192,"identity":"d12ee278-7ebf-4919-809d-75e0fc226ab8","added_by":"auto","created_at":"2025-09-08 09:37:13","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":170479,"visible":true,"origin":"","legend":"\u003cp\u003eDrawings of sclerotized parts of \u003cem\u003eA. maillardii\u003c/em\u003e, Va = ventral anchor; Da = dorsal anchor; VB = ventral bar; DB = dorsal bar; HI-HVII = hooks (pairs I-VII); MCO = male copulatory organ\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-7468163/v1/b1f50b0b7c2847dcbb881ca8.png"},{"id":90799007,"identity":"679d8133-9df1-4003-bc28-30b40b9e6d8e","added_by":"auto","created_at":"2025-09-08 09:45:13","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":157426,"visible":true,"origin":"","legend":"\u003cp\u003eDrawings of sclerotized parts of \u003cem\u003eA. bouixi\u003c/em\u003e, Va = ventral anchor; Da = dorsal anchor; VB = ventral bar; DB = dorsal bar; HI-HVII = hooks (pairs I-VII); MCO = male copulatory organ; Vag = vagina\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-7468163/v1/520843f224cc3f2525def60a.png"},{"id":90798193,"identity":"0d0ef889-3758-487a-a469-4d688ded8652","added_by":"auto","created_at":"2025-09-08 09:37:13","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":134855,"visible":true,"origin":"","legend":"\u003cp\u003eDrawings of sclerotized parts of \u003cem\u003eA. bouixi\u003c/em\u003e, Va = ventral anchor; Da = dorsal anchor; VB = ventral bar; DB = dorsal bar; HI-HVII = hooks (pairs I-VII); MCO = male copulatory organ\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-7468163/v1/03ce98245747c248f84816e3.png"},{"id":90799220,"identity":"f6bbbf66-7d16-482f-ba18-ccc2372372d4","added_by":"auto","created_at":"2025-09-08 09:53:13","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":118289,"visible":true,"origin":"","legend":"\u003cp\u003eDrawings of sclerotized parts of \u003cem\u003eA. amieti\u003c/em\u003e,\u003cem\u003e \u003c/em\u003eVa = ventral anchor; Da = dorsal anchor; VB = ventral bar; DB = dorsal bar; HI-HVII = hooks (pairs I-VII); MCO = male copulatory organ; Vag = vagina\u003c/p\u003e","description":"","filename":"6.png","url":"https://assets-eu.researchsquare.com/files/rs-7468163/v1/cc5dd7678f9e6aa0583a3b1d.png"},{"id":90799011,"identity":"b49b4964-7e56-4377-a1b6-96d3f2b339fc","added_by":"auto","created_at":"2025-09-08 09:45:13","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":94204,"visible":true,"origin":"","legend":"\u003cp\u003eDrawings of sclerotized parts of \u003cem\u003eA. amieti \u003c/em\u003eVa = ventral anchor, Da = dorsal anchor, VB = ventral bar, DB = dorsal bar, HI-HVII = hooks (pairs I-VII), MCO = male copulatory organ, Vag = vagina\u003c/p\u003e","description":"","filename":"7.png","url":"https://assets-eu.researchsquare.com/files/rs-7468163/v1/2c1a8c34847bb04cfa7a6a2c.png"},{"id":90799010,"identity":"9ad5f3dd-ecdf-4389-8dca-9b73d470870f","added_by":"auto","created_at":"2025-09-08 09:45:13","extension":"png","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":156344,"visible":true,"origin":"","legend":"\u003cp\u003eDrawings of sclerotized parts of \u003cem\u003eA. hepseti \u003c/em\u003eVa = ventral anchor, Da = dorsal anchor, VB = ventral bar, DB = dorsal bar, HI-HVII = hooks (pairs I-VII), MCO = male copulatory organ, Vag = vagina\u003c/p\u003e","description":"","filename":"8.png","url":"https://assets-eu.researchsquare.com/files/rs-7468163/v1/3ef5dc93d70cf9aee0ca74be.png"},{"id":90798200,"identity":"4ee75fa8-bf64-4863-b286-2b95fbcdc69a","added_by":"auto","created_at":"2025-09-08 09:37:13","extension":"png","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":71614,"visible":true,"origin":"","legend":"\u003cp\u003ePrincipal component analysis of the contribution of 23 variables to the first two component calculated from 18 species of \u003cem\u003eAnnulotrema\u003c/em\u003erecorded in Cameroon\u003c/p\u003e","description":"","filename":"9.png","url":"https://assets-eu.researchsquare.com/files/rs-7468163/v1/69d5f92e56223fbcb1aa5bdc.png"},{"id":90798207,"identity":"1664aa79-3e96-4084-907b-f3f4016ac1e1","added_by":"auto","created_at":"2025-09-08 09:37:13","extension":"png","order_by":10,"title":"Figure 10","display":"","copyAsset":false,"role":"figure","size":100943,"visible":true,"origin":"","legend":"\u003cp\u003ePrincipal component Analysis of \u003cem\u003eAnnulotrema\u003c/em\u003e species recorded in Cameroon, an isolation of individuals of \u003cem\u003eA. ngombiensis\u003c/em\u003e (black rectangle), \u003cem\u003eA. nkengfacki\u003c/em\u003e, \u003cem\u003eA.gabrioni\u003c/em\u003eand \u003cem\u003eA. nyongensis\u003c/em\u003e are very closely related (red rectangle), two of the three species of the \u003cem\u003eAmieti\u003c/em\u003e morphogroup show strong affinities with the \u003cem\u003eHepseti\u003c/em\u003e morphogroup (circle)\u003c/p\u003e","description":"","filename":"10.png","url":"https://assets-eu.researchsquare.com/files/rs-7468163/v1/ce82757a492ac7d40e214b45.png"},{"id":90799960,"identity":"57a40206-4565-4961-aabc-dba15b9eae2a","added_by":"auto","created_at":"2025-09-08 10:01:15","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2980233,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7468163/v1/4a6e3104-5407-454e-bbeb-2b9881681182.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Integrative taxonomy of Annulotrema (Monogenea: Dactylogyridae) from some Characiformes of Cameroon: Redescriptions and morphogroup delimitation using numerical phylogeny","fulltext":[{"header":"1- Introduction","content":"\u003cp\u003eThe order of Characiformes includes 3 families, 20 genera and about 53 species of fish, the majority of which belong to the Alestidae family (Stiassny, 2007). These fish are widely consumed in Africa. In addition to their flavour, the interest of populations in these freshwater teleost also lies in their movement in schools which facilitates their capture (Brummet, 1988). The enormous losses recorded by fish farmers wishing to cultivate some Characidae such as \u003cem\u003eBrycinus macrolepidotus\u003c/em\u003e Valenciennes, 1849 have contributed to the non-existence of Characiform fish production policies in some African countries, notably Cameroon (Ndongo, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e2025\u003c/span\u003e). Gill monogeneans are to some extent responsible for the massive losses recorded in aquaculture, so it would be essential to conduct a study of this group of parasites before embarking on a fish farming project (Bilong Bilong, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e1995\u003c/span\u003e; Buchmann \u0026amp; Lindenstrom, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2002\u003c/span\u003e). Characidea are host monogeneans of the genera \u003cem\u003eAfrocleidodiscus\u003c/em\u003e (1 species), \u003cem\u003eCharacidotrema\u003c/em\u003e (11 species) and \u003cem\u003eAnnulotrema\u003c/em\u003e (57 species) (Řehulkov\u0026aacute; et al., \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e2019\u003c/span\u003e; Kičinjaov\u0026aacute; et al., \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2024\u003c/span\u003e). Note that only the last two genera have already been recorded in Cameroon. Until 2023, the only available data on monogeneans of Characiformes in Cameroon came from Birgi (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e1988\u003c/span\u003e) which allowed the description of 17 species of \u003cem\u003eAnnulotrema\u003c/em\u003e and the establishment of five morphogroups. It is only very recently that Ndongo et al. (\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2023\u003c/span\u003e) discovered two \u003cem\u003eAnnulotrema\u003c/em\u003e which exploit \u003cem\u003eB. macrolepidotus\u003c/em\u003e in the Nyong River. Proving that this group of parasites remains very little known in our country. The present work is therefore the continuation of the study carried out by Ndongo et al. (\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2023\u003c/span\u003e) and aims to revisit the diagnosis of certain \u003cem\u003eAnnulotrema\u003c/em\u003e from Cameroon and to highlight their morphometric links.\u003c/p\u003e"},{"header":"2- Materials and methods","content":"\u003cp\u003e\u003cb\u003e2-1- Fish sampling\u003c/b\u003e\u003c/p\u003e\u003cp\u003eFrom February 2019 to December 2020, fish catches were made by local fishermen using nets of varying mesh sizes (1cm x 1cm, 2.5 cm x 2.5) in the lowersins of the Dibamba and Nyong on its main course in Akonolinga, and in the Mefou and Akono rivers in Yaound\u0026eacute; (respectively in the villages of Afanoyoa and Bingu\u0026eacute;la) (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). These fishes were kept in the icebox with ice inside.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\n\u003ch3\u003e2-2- Parasitological analysis and morphological characterisation\u003c/h3\u003e\n\u003cp\u003eAfter the dissection of fish, each gill were removed and isolated in Petri dishes containing tap water. Then, each monogenean was dislodged from the gill with fine needle and mounted between slide and coverslip (in situ or in the laboratory located at the University of Yaound\u0026eacute; I). Each monogenean was mounted in a drop of mixture of glycerine and ammonium picrate and the slides were sealed 72 hours later with glyceel (Malmberg, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e1957\u003c/span\u003e; Bates, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e1997\u003c/span\u003e). The microphotographs of the different sclerotized parts of the haptor and the genital apparatus were taken with the Amscope MU 408 microphotography device connected to a computer and the YVYMEN optical microscope. These photographs were subsequently analysed using Amscope and Corel Draw X8 software respectively to determine the measurements of the different sclerotized pieces and to produce drawings of the latter. The different measurements and nomenclatures were made respectively according to Ndongo et al. (\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2023\u003c/span\u003e) and ICOPA IV (Euzet and Prost, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e1981\u003c/span\u003e). The different measurements are presented in micrometres according to the mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation (minimum-maximum) model (when n\u0026thinsp;\u0026ge;\u0026thinsp;10 individuals). The paratypes were kept at the National Museum of Natural History in Paris (MNHN).\u003c/p\u003e\n\u003ch3\u003e2-3- multivariate analysis\u003c/h3\u003e\n\u003cp\u003eTo visualise the morphological links between the species, a principal component analysis (PCA) was performed using SPSS software v26.0. The analyses included 23 measurements from the haptorial pieces and the male copulatory organ (MCO). Each measurements was converted into ratio by dividing its value by that of the hook II (as its size varies little with the size of the animal). The body length of the animal was not considered. The species and the variables of the sclerotized parts considered for this study are respectively listed in Table \u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e and Table \u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\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\u003eVariables used to establish morphometric links between \u003cem\u003eAnnulotrema\u003c/em\u003e species recorded in Cameroon\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"3\"\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\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eMCO\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eTotal length\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHooks\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eH\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eI\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eTotal length\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eIII\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eTotal length\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eIV\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eTotal length\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eV\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eTotal length\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eVI\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eTotal length\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eVII\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eTotal length\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eVentral bar\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eVB\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eVBL\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eTotal length\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eVBW\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eTotal width\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e10\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eVBMW\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eMedian width\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDorsal bar\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eDB\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e11\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eDBL\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eTotal length\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e12\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eDBW\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eTotal width\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e13\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eDBMW\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eMedian width\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eVentral anchor\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eVA\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e14\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eVAI\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eInner length\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eVAE\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eOuter length\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e16\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eVAIR\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eInner root length\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e17\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eVAOR\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eOuter root length\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e18\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eVAP\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003ePoint length\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDorsal anchor\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cb\u003eDA\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e19\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eDAI\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eInner length\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e20\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eDAO\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eOuter length\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e21\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eDAIR\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eInner root length\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e22\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eDAOR\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eOuter root length\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e23\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eDAP\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003ePoint length\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\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\u003eList of \u003cem\u003eAnnulotrema\u003c/em\u003e species (with type-host and locality) from Cameroun whose sclerotized parts measurements were used for the PCA with their respective morphogroups established by Birgi, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e1988\u003c/span\u003e\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\u003eLocality\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eAuthority\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eMorphogroup\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\u003eA. combesi\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cem\u003eBrycinus kingsleyae\u003c/em\u003e G\u0026uuml;nther,1986\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eEbogo: Nyong River\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eBirgi, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e1988\u003c/span\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cem\u003eCombesi\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cem\u003eA. nyongensis\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cem\u003eBrycinus kingsleyae\u003c/em\u003e G\u0026uuml;nther,1986\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eEbogo: Nyong River\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eBirgi, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e1988\u003c/span\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\" morerows=\"1\" rowspan=\"2\"\u003e\u003cp\u003e\u003cem\u003eNyongensis\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cem\u003eA. gabrioni\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cem\u003ePhenacogrammus major\u003c/em\u003e Boulenger, 1903 et \u003cem\u003eHemigrammopetersius pulcher\u003c/em\u003e Boulenger, 1909\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eSangmelima: Dja River\u003c/p\u003e\u003cp\u003eYaound\u0026eacute;: Nyong River\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eBirgi, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e1988\u003c/span\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cem\u003eA. amieti*\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cem\u003ePhenacogrammus major\u003c/em\u003e Boulenger, 1903 et \u003cem\u003eHemigrammopetersius pulcher\u003c/em\u003e Boulenger, 1909\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eSangmelima: Dja River\u003c/p\u003e\u003cp\u003eYaound\u0026eacute;: Nyong River\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eBirgi, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e1988\u003c/span\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\" morerows=\"7\" rowspan=\"8\"\u003e\u003cp\u003e\u003cem\u003eAmieti\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cem\u003eA. bouixi\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cem\u003eBrycinus kingsleyae\u003c/em\u003e G\u0026uuml;nther, 1986\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eEbogo: Nyong River\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eBirgi, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e1988\u003c/span\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cem\u003eA. edeensis*\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cem\u003eMicralestes sp\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eSomakek: Sanaga River\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eBirgi, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e1988\u003c/span\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cem\u003eA. kribiensis*\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cem\u003eBrycinus longipinnis\u003c/em\u003e G\u0026uuml;nther, 1864\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eMoanko: Sanaga River\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eBirgi, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e1988\u003c/span\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cem\u003eA. lamberti*\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cem\u003eBrycinus longipinnis\u003c/em\u003e G\u0026uuml;nther, 1864\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eMoanko: Sanaga River\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eBirgi, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e1988\u003c/span\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cem\u003eA. maillardi\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cem\u003eBrycinus kingsleyae\u003c/em\u003e G\u0026uuml;nther,1986\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eEbogo: Nyong River\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eBirgi, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e1988\u003c/span\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cem\u003eA. moanko*\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cem\u003eBrycinus longipinnis\u003c/em\u003e G\u0026uuml;nther, 1864\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eMoanko: Sanaga River\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eBirgi, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e1988\u003c/span\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cem\u003eA. sangmelinensis*\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cem\u003eMicralestes humilis\u003c/em\u003e Boulenger, 1899\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eSangmelima: Dja River\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eBirgi, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e1988\u003c/span\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cem\u003eA. nannoethiopis*\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cem\u003eNannoethiopis unitoeniatus\u003c/em\u003e G\u0026uuml;nther, 1872\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eNkolya: Nyong River\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eBirgi, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e1988\u003c/span\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\" morerows=\"3\" rowspan=\"4\"\u003e\u003cp\u003e\u003cem\u003eNannoethiopis\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cem\u003eA. bilongi*\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cem\u003eNeolebias trewavasae\u003c/em\u003e Poll et Goss, 1963\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eNkolya: Nyong River\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eBirgi, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e1988\u003c/span\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cem\u003eA. endjami*\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cem\u003eNeolebias trewavasae\u003c/em\u003e Poll et Goss, 1963\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eNkolya: Nyong River\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eBirgi, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e1988\u003c/span\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cem\u003eA. fomenai*\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cem\u003eNeolebias trewavasae\u003c/em\u003e Poll et Goss, 1963\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eNkolya: Nyong River\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eBirgi, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e1988\u003c/span\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cem\u003eA. hepseti\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cem\u003eHepsetus odoe\u003c/em\u003e Block, 1794\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eNyong River\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003ePaperna and Thurston, 1969\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cem\u003eHepseti\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cem\u003eA. ngombiensis**\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cem\u003eBrycinus macrolepidotus\u003c/em\u003e Valenciennes, 1849\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eAkonolinga: Nyong River\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eNdongo and Tombi, 2023\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e???\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e\u003cem\u003eA. nkengfacki**\u003c/em\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e\u003cem\u003eBrycinus macrolepidotus\u003c/em\u003e Valenciennes, 1849\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eAkonolinga: Nyong River\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eNdongo and Tombi, 2023\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e???\u003c/b\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\u003e\u003cb\u003e???\u003c/b\u003e : The morphogroup of this species will be determined after the analysis; *: sclerotized parts measurements obtained from Birgi (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e1988\u003c/span\u003e); **: sclerotized parts measurements obtained from Ndongo et al. (\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2023\u003c/span\u003e)\u003c/p\u003e"},{"header":"3- Results","content":"\u003cp\u003e\u003cb\u003e3-1- Morphological description\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eAnnulotrema combesi\u003c/b\u003e Birgi, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e1988\u003c/span\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eType host\u003c/b\u003e: \u003cb\u003eBrycinus kingsleyae\u003c/b\u003e \u003cb\u003eG\u0026uuml;nther, 1896\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eType locality: Nyong River in Ebogo, Cameroon\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eOther localities: Nyong Cameroun Melan (3\u0026deg;46' 11.424''N; 12\u0026deg;16' 22.236''E), Sombo (3\u0026deg;46' 13.548''N; 12\u0026deg;16' 27.612''E)\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eInfestation site: Gills\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003ePrevalence: 5% (2 parasitized fish out of 40 fish examined)\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eNumber of individuals studied: 2 mounted in Malmberg liquid\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eType specimen: Paratype MNHN HEL 2076\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eRedescription (\u003c/b\u003eFig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e\u003cb\u003e)\u003c/b\u003e\u003c/p\u003e\u003cp\u003eTotal length\u0026thinsp;=\u0026thinsp;454\u0026ndash;455; pharyngeal width\u0026thinsp;=\u0026thinsp;104; ovary width\u0026thinsp;=\u0026thinsp;131\u0026ndash;133. Haptor width\u0026thinsp;=\u0026thinsp;98\u0026ndash;99. Ventral anchors without filaments, robust, arched with a reduced point. Inner length\u0026thinsp;=\u0026thinsp;57\u0026ndash;58; outer length\u0026thinsp;=\u0026thinsp;58\u0026ndash;59. Inner root length\u0026thinsp;=\u0026thinsp;18; outer root length\u0026thinsp;=\u0026thinsp;8\u0026ndash;10 and point length\u0026thinsp;=\u0026thinsp;2\u0026ndash;3. Dorsal anchors filiform with a vestigial inner root, a long outer root and a reduced point. Inner length\u0026thinsp;=\u0026thinsp;52\u0026ndash;53; outer root length\u0026thinsp;=\u0026thinsp;20\u0026ndash;24 and point length\u0026thinsp;=\u0026thinsp;1\u0026ndash;3. Ventral bar with swollen ends. The anterior side forms an accolade. Total length\u0026thinsp;=\u0026thinsp;23\u0026ndash;24; Total width\u0026thinsp;=\u0026thinsp;8\u0026ndash;9, median width\u0026thinsp;=\u0026thinsp;6 and diameter of the median loop\u0026thinsp;=\u0026thinsp;3. Very thin dorsal bar forms a lying 7. Total length\u0026thinsp;=\u0026thinsp;20\u0026ndash;21; total width\u0026thinsp;=\u0026thinsp;7 and median width\u0026thinsp;=\u0026thinsp;2. Hooks with filament; pairs I to V more robust. Pair I\u0026thinsp;=\u0026thinsp;9\u0026ndash;10; pair II\u0026thinsp;=\u0026thinsp;15\u0026ndash;16; pair III\u0026thinsp;=\u0026thinsp;27\u0026ndash;28; pair IV\u0026thinsp;=\u0026thinsp;25\u0026ndash;27; pair V\u0026thinsp;=\u0026thinsp;23\u0026ndash;24; pair VI\u0026thinsp;=\u0026thinsp;22\u0026ndash;23; pair VII\u0026thinsp;=\u0026thinsp;23\u0026ndash;24. The male copulatory organ (MCO) begins with an oval basal bulb fused to an elongated accessory part. The copulatory tube makes two turns of the spire in the counter clockwise direction before sliding into the distal part of the accessory part. Total length\u0026thinsp;=\u0026thinsp;28\u0026ndash;29; tube trace length\u0026thinsp;=\u0026thinsp;148\u0026ndash;149; diameter of the first turn of the spire\u0026thinsp;=\u0026thinsp;16\u0026ndash;17; diameter of second turn of spire\u0026thinsp;=\u0026thinsp;28\u0026ndash;29; distance between turns of spire\u0026thinsp;=\u0026thinsp;5; base length\u0026thinsp;=\u0026thinsp;9 and base width\u0026thinsp;=\u0026thinsp;6. The vagina was not observed.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eRemarks\u003c/b\u003e\u003c/p\u003e\u003cp\u003eThe description was made by Birgi (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e1988\u003c/span\u003e) in the same host in the Nyong River. Some characteristics observed during this redescription do not coincide with those presented during the original description. Indeed, the arrangement of the accessory part in relation to the copulatory tube does not correspond to that presented by Birgi (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e1988\u003c/span\u003e). Furthermore, for this author, the copulatory tube describes one turn of spire compared to two in the present study. In addition, the measurements of hooks I and II reported by Birgi (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e1988\u003c/span\u003e) are larger (50 and 20 \u0026micro;m respectively) compared to ours (9 and 15 \u0026micro;m respectively). We nevertheless believe that these differences are not sufficient to separate the present species from \u003cem\u003eA. combesi\u003c/em\u003e. We prefer so for the moment to attach the specimens obtained to this species.\u003c/p\u003e\u003cp\u003e\u003cb\u003eAnnulotrema maillardi\u003c/b\u003e Birgi, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e1988\u003c/span\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eType host\u003c/b\u003e: \u003cb\u003eBrycinus kingsleyae\u003c/b\u003e \u003cb\u003eG\u0026uuml;nther, 1986\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eType locality: Nyong River in Ebogo, Cameroon\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eOther localities: Nyong: Melan (3\u0026deg;46' 11.424''N; 12\u0026deg;16' 22.236''E), Sombo (3\u0026deg;46' 13.548''N; 12\u0026deg;16' 27.612''E), Nyong Bridge Cameroon (3\u0026deg;46' 10.53''N; 12\u0026deg;14' 49.062 E); Mefou River at Afanoyo'o (3\u0026deg;44' 60''N; 11\u0026deg;27' 51''E).\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eInfestation site: Gills\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003ePrevalence: 20% (8 parasitized fish out of 40 examined)\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eNumber of individuals studied: 10 mounted in Malmberg liquid\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eType specimen: Paratype MNHN HEL2077\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eRedescription (\u003c/b\u003eFig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e\u003cb\u003e)\u003c/b\u003e\u003c/p\u003e\u003cp\u003eTotal length\u0026thinsp;=\u0026thinsp;569\u0026thinsp;\u0026plusmn;\u0026thinsp;46.38 (508\u0026ndash;636); width at pharynx\u0026thinsp;=\u0026thinsp;101\u0026thinsp;\u0026plusmn;\u0026thinsp;8.81 (89\u0026ndash;110) and width at ovaries\u0026thinsp;=\u0026thinsp;148\u0026thinsp;\u0026plusmn;\u0026thinsp;35.01 (102\u0026ndash;177). Haptor width\u0026thinsp;=\u0026thinsp;88\u0026thinsp;\u0026plusmn;\u0026thinsp;27.34 (45\u0026ndash;122). Robust ventral anchors with filament, reduced outer root and marked point. Inner length\u0026thinsp;=\u0026thinsp;45\u0026thinsp;\u0026plusmn;\u0026thinsp;1.7 (43\u0026ndash;48); outer length\u0026thinsp;=\u0026thinsp;41\u0026thinsp;\u0026plusmn;\u0026thinsp;1.3 (39\u0026ndash;43); inner root length\u0026thinsp;=\u0026thinsp;15\u0026thinsp;\u0026plusmn;\u0026thinsp;1.88 (14\u0026ndash;18); outer root length\u0026thinsp;=\u0026thinsp;5\u0026thinsp;\u0026plusmn;\u0026thinsp;0.59 (4\u0026ndash;6) and point length\u0026thinsp;=\u0026thinsp;5\u0026thinsp;\u0026plusmn;\u0026thinsp;0.75 (3\u0026ndash;6). Thin, elongated dorsal anchors with filament, developed inner root and marked point. Inner length\u0026thinsp;=\u0026thinsp;50\u0026thinsp;\u0026plusmn;\u0026thinsp;3.21 (47\u0026ndash;53); outer length\u0026thinsp;=\u0026thinsp;35\u0026thinsp;\u0026plusmn;\u0026thinsp;1.9 (33\u0026ndash;38); inner root length\u0026thinsp;=\u0026thinsp;24\u0026thinsp;\u0026plusmn;\u0026thinsp;1.93 (21\u0026ndash;27); outer root length\u0026thinsp;=\u0026thinsp;7\u0026thinsp;\u0026plusmn;\u0026thinsp;1.81 (5\u0026ndash;10) and point length\u0026thinsp;=\u0026thinsp;4\u0026thinsp;\u0026plusmn;\u0026thinsp;0.84 (3\u0026ndash;5). Ventral bar with swollen ends with a thin median part and membranous extension on the basal side. Total length\u0026thinsp;=\u0026thinsp;25\u0026thinsp;\u0026plusmn;\u0026thinsp;2.5 (22\u0026ndash;27); total width\u0026thinsp;=\u0026thinsp;16\u0026thinsp;\u0026plusmn;\u0026thinsp;2.55 (13\u0026ndash;19) and median width\u0026thinsp;=\u0026thinsp;12\u0026thinsp;\u0026plusmn;\u0026thinsp;2.47 (8\u0026ndash;15). Triangular dorsal bar surmounted by a thin rectilinear structure. Total length\u0026thinsp;=\u0026thinsp;23\u0026thinsp;\u0026plusmn;\u0026thinsp;2 (20\u0026ndash;26); total width\u0026thinsp;=\u0026thinsp;12\u0026thinsp;\u0026plusmn;\u0026thinsp;1.08 (11\u0026ndash;14) and median width\u0026thinsp;=\u0026thinsp;9\u0026thinsp;\u0026plusmn;\u0026thinsp;0.74 (8\u0026ndash;10). Dissimilar hooks, robust and without filament. Pair I\u0026thinsp;=\u0026thinsp;20\u0026thinsp;\u0026plusmn;\u0026thinsp;1.71 (17\u0026ndash;22); pair II\u0026thinsp;=\u0026thinsp;10\u0026thinsp;\u0026plusmn;\u0026thinsp;0.89 (8\u0026ndash;11); pair III\u0026thinsp;=\u0026thinsp;23\u0026thinsp;\u0026plusmn;\u0026thinsp;5.15 (17\u0026ndash;34); pair IV\u0026thinsp;=\u0026thinsp;27\u0026thinsp;\u0026plusmn;\u0026thinsp;1.02 (26\u0026ndash;29); pair V\u0026thinsp;=\u0026thinsp;29\u0026thinsp;\u0026plusmn;\u0026thinsp;1.13 (28\u0026ndash;31); pair VI\u0026thinsp;=\u0026thinsp;25\u0026thinsp;\u0026plusmn;\u0026thinsp;1.17 (25\u0026ndash;28); pair VII\u0026thinsp;=\u0026thinsp;22\u0026thinsp;\u0026plusmn;\u0026thinsp;2.31 (19\u0026ndash;26). The MCO begins with an oval basal ampulla. Penis rotates counter clockwise, a thin, flat accessory part fused to the basal ampulla. Total length\u0026thinsp;=\u0026thinsp;21\u0026thinsp;\u0026plusmn;\u0026thinsp;0.99 (20\u0026ndash;22); tube trace length\u0026thinsp;=\u0026thinsp;49\u0026thinsp;\u0026plusmn;\u0026thinsp;1.15 (48\u0026ndash;51); base length\u0026thinsp;=\u0026thinsp;6\u0026thinsp;\u0026plusmn;\u0026thinsp;0.72 (5\u0026ndash;7) and base width\u0026thinsp;=\u0026thinsp;4\u0026thinsp;\u0026plusmn;\u0026thinsp;0.48 (3\u0026ndash;5). The vagina was not observed.\u003c/p\u003e\u003cp\u003e\u003cb\u003eRemarks\u003c/b\u003e\u003c/p\u003e\u003cp\u003eThe morphology of the MCO of the parasite redescribed in this paper is reminiscent of that of \u003cem\u003eAnnulotrema maillardi\u003c/em\u003e Birgi, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e1988\u003c/span\u003e collected from the gills of the same host species in the Nyong River at Ebogo in Cameroon. However, the specimens observed during the current study show some differences compared to the original description of this species. Indeed, the ventral bar described by Birgi is a simple convex quadrilateral while the specimens in the present study have a flattened dorsal bar with a mid-basal extension. In addition, in Birgi (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e1988\u003c/span\u003e) the dorsal bar is a quadrilateral with narrowed edges while in our specimens, this bar is triangular and surmounted by a median sclerotized piece. Given that the morphology of the genital parts corresponds to that of \u003cem\u003eA. maillardi\u003c/em\u003e, we assign the specimens studied to this species.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eAnnulotrema bouixi\u003c/b\u003e Birgi, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e1988\u003c/span\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eType host\u003c/b\u003e: \u003cb\u003eBrycinus kingsleyae\u003c/b\u003e \u003cb\u003eG\u0026uuml;nther, 1986\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eType locality: Nyong River in Ebogo, Cameroon\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eOther localities: Nyong at Melan (3\u0026deg;46' 11.424''N ; 12\u0026deg;16' 22.236''E), Sombo (3\u0026deg;46' 13.548''N ; 12\u0026deg;16' 27.612''E), Pont (3\u0026deg;46' 10.53''N ; 12\u0026deg;14' 49.062 E); Mefou River at Afanoyo'o (3\u0026deg;44' 60''N ; 11\u0026deg;27' 51''E)\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eInfestation site: Gills\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003ePrevalence: 75% (30 parasitized fish out of 40 fish examined)\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eNumber of individuals examined: 10 mounted in Malmberg liquid\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eType specimen: Paratype MNHN HEL2078\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eRedescription (\u003c/b\u003eFig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e\u003cb\u003e)\u003c/b\u003e\u003c/p\u003e\u003cp\u003eBody length 423\u0026thinsp;\u0026plusmn;\u0026thinsp;49.99 (370\u0026ndash;489); width of pharynx 63\u0026thinsp;\u0026plusmn;\u0026thinsp;14.84 (44\u0026ndash;93); width at ovaries 82\u0026thinsp;\u0026plusmn;\u0026thinsp;11.43 (61\u0026ndash;100) and width of haptor 80\u0026thinsp;\u0026plusmn;\u0026thinsp;13.43 (52\u0026ndash;95). Robust ventral anchors with filaments and with well-individualized inner root and outer root. Arched blade and reduced point. Inner length\u0026thinsp;=\u0026thinsp;28\u0026thinsp;\u0026plusmn;\u0026thinsp;2.26 (24\u0026ndash;29); outer length\u0026thinsp;=\u0026thinsp;31\u0026thinsp;\u0026plusmn;\u0026thinsp;2.15 (28\u0026ndash;30); inner root length\u0026thinsp;=\u0026thinsp;10\u0026thinsp;\u0026plusmn;\u0026thinsp;1.49 (9\u0026ndash;13); outer root length\u0026thinsp;=\u0026thinsp;7\u0026thinsp;\u0026plusmn;\u0026thinsp;1.71 (4\u0026ndash;9); point length\u0026thinsp;=\u0026thinsp;3\u0026thinsp;\u0026plusmn;\u0026thinsp;0.36 (3\u0026ndash;4). Dorsal anchors swollen at the inner root-outer root connection with filament and marked point. Inner length\u0026thinsp;=\u0026thinsp;34\u0026thinsp;\u0026plusmn;\u0026thinsp;2.11 (31\u0026ndash;37); outer length\u0026thinsp;=\u0026thinsp;27\u0026thinsp;\u0026plusmn;\u0026thinsp;2.63 (26\u0026ndash;29); inner root length\u0026thinsp;=\u0026thinsp;13\u0026thinsp;\u0026plusmn;\u0026thinsp;1.70 (12\u0026ndash;15); outer root length\u0026thinsp;=\u0026thinsp;4\u0026thinsp;\u0026plusmn;\u0026thinsp;1.58 (3\u0026ndash;8); point length\u0026thinsp;=\u0026thinsp;3\u0026thinsp;\u0026plusmn;\u0026thinsp;0.44 (3\u0026ndash;4). Rectangular ventral bar, forms a thick, slightly curved blade with a mid-basal part connected by a thin longitudinal sclerotization to another, less thick, parallel blade (reminiscent of the shape of an inverted T). Total length\u0026thinsp;=\u0026thinsp;21\u0026thinsp;\u0026plusmn;\u0026thinsp;2.54 (18\u0026ndash;27); total width\u0026thinsp;=\u0026thinsp;11\u0026thinsp;\u0026plusmn;\u0026thinsp;1.57 (11\u0026ndash;13); median width\u0026thinsp;=\u0026thinsp;9\u0026thinsp;\u0026plusmn;\u0026thinsp;0.88 (7\u0026ndash;10); T-bar length\u0026thinsp;=\u0026thinsp;12\u0026thinsp;\u0026plusmn;\u0026thinsp;2.77 (8\u0026ndash;13). Y-shaped dorsal bar. Total length\u0026thinsp;=\u0026thinsp;21\u0026thinsp;\u0026plusmn;\u0026thinsp;2.12 (18\u0026ndash;23); total width\u0026thinsp;=\u0026thinsp;14\u0026thinsp;\u0026plusmn;\u0026thinsp;1.80 (11\u0026ndash;17); median width\u0026thinsp;=\u0026thinsp;9\u0026thinsp;\u0026plusmn;\u0026thinsp;1.38 (8\u0026ndash;11). Dissimilar hooks with filaments on pairs III to VII. Pair I\u0026thinsp;=\u0026thinsp;16\u0026thinsp;\u0026plusmn;\u0026thinsp;1.28 (14\u0026ndash;18); pair II\u0026thinsp;=\u0026thinsp;9\u0026thinsp;\u0026plusmn;\u0026thinsp;0.89 (8\u0026ndash;10); pair III\u0026thinsp;=\u0026thinsp;21\u0026thinsp;\u0026plusmn;\u0026thinsp;1.98 (20\u0026ndash;24); pair IV\u0026thinsp;=\u0026thinsp;22\u0026thinsp;\u0026plusmn;\u0026thinsp;2.13 (19\u0026ndash;25); pair V\u0026thinsp;=\u0026thinsp;25\u0026thinsp;\u0026plusmn;\u0026thinsp;3.6 (19\u0026ndash;27); pair VI\u0026thinsp;=\u0026thinsp;21\u0026thinsp;\u0026plusmn;\u0026thinsp;2.43 (16\u0026ndash;23); pair VII\u0026thinsp;=\u0026thinsp;18\u0026thinsp;\u0026plusmn;\u0026thinsp;2.9 (13\u0026ndash;23). The MCO with oval basal bulb fused to the basal part of the accessory piece, describes a clockwise loop. Total length\u0026thinsp;=\u0026thinsp;20\u0026thinsp;\u0026plusmn;\u0026thinsp;2.03 (18\u0026ndash;25); tube trace length\u0026thinsp;=\u0026thinsp;46\u0026thinsp;\u0026plusmn;\u0026thinsp;5.10 (40\u0026ndash;55); base length\u0026thinsp;=\u0026thinsp;4\u0026thinsp;\u0026plusmn;\u0026thinsp;0.35 (3\u0026ndash;4) and base width\u0026thinsp;=\u0026thinsp;4\u0026thinsp;\u0026plusmn;\u0026thinsp;0.73 (3\u0026ndash;4). The vagina is tubular and pediform with Length\u0026thinsp;=\u0026thinsp;26.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eRemarks\u003c/b\u003e\u003c/p\u003e\u003cp\u003eThe size of the specimens collected during this study, the morphology and the measurements of the different sclerotized parts of the haptor and the copulatory apparatus correspond to those of \u003cem\u003eAnnulotrema bouixi\u003c/em\u003e Birgi, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e1988\u003c/span\u003e described on the gills of \u003cem\u003eB. kingsleyae\u003c/em\u003e captured in the Nyong River in the village of Ebogo. The only difference lies in the lower blade of the ventral bar, the size of which is larger than that mentioned in the original description (8\u0026ndash;12 vs 4). This minimal difference allows us to link the present specimens to those of the species \u003cem\u003eAnnulotrema bouixi\u003c/em\u003e.\u003c/p\u003e\u003cp\u003e\u003cb\u003eAnnulotrema nyongensis\u003c/b\u003e Birgi, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e1988\u003c/span\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eType host\u003c/b\u003e: \u003cb\u003eBrycinus kingsleyae\u003c/b\u003e \u003cb\u003eG\u0026uuml;nther, 1986\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eType locality: Nyong River in Ebogo, Cameroon\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eOther localities: Nyong at Melan (3\u0026deg;46' 11.424''N ; 12\u0026deg;16' 22.236''E), Sombo (3\u0026deg;46' 13.548''N ; 12\u0026deg;16' 27612''E), Pont (3\u0026deg;46' 10.53''N ; 12\u0026deg;14' 49.062 E); Mefou River at Afanoyo'o (3\u0026deg;44' 60''N ; 11\u0026deg;27' 51''E)\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eInfestation site: Gills\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003ePrevalence: 25% (10 parasitized fish out of 40 fish examined)\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eNumber of individuals examined: 10 mounted in Malmberg liquid\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eType specimen: Paratype MNHN HEL 2079\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eRedescription (\u003c/b\u003eFig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e\u003cb\u003e)\u003c/b\u003e\u003c/p\u003e\u003cp\u003eBody length\u0026thinsp;=\u0026thinsp;355\u0026thinsp;\u0026plusmn;\u0026thinsp;16.03 (338\u0026ndash;379); width at the pharynx\u0026thinsp;=\u0026thinsp;54\u0026thinsp;\u0026plusmn;\u0026thinsp;6.58 (44\u0026ndash;62); width at the ovaries\u0026thinsp;=\u0026thinsp;76\u0026thinsp;\u0026plusmn;\u0026thinsp;12.69 (58\u0026ndash;93); haptor width\u0026thinsp;=\u0026thinsp;67\u0026thinsp;\u0026plusmn;\u0026thinsp;10.73 (48\u0026ndash;89). Ventral anchors with inner root and outer root not very individual, much-arched blade and little marked point. Inner length\u0026thinsp;=\u0026thinsp;21\u0026thinsp;\u0026plusmn;\u0026thinsp;0.49 (20\u0026ndash;22); outer length\u0026thinsp;=\u0026thinsp;24\u0026thinsp;\u0026plusmn;\u0026thinsp;0.52 (23\u0026ndash;24); inner root length\u0026thinsp;=\u0026thinsp;8\u0026thinsp;\u0026plusmn;\u0026thinsp;0.49 (8\u0026ndash;9); outer root length\u0026thinsp;=\u0026thinsp;5\u0026thinsp;\u0026plusmn;\u0026thinsp;0.92 (3\u0026ndash;6); point length\u0026thinsp;=\u0026thinsp;1\u0026thinsp;\u0026plusmn;\u0026thinsp;0.18 (1\u0026ndash;2). Dorsal anchors less robust than the ventral ones, inner root and outer root well individualized. Thin blade with reduced point. Inner length\u0026thinsp;=\u0026thinsp;24\u0026thinsp;\u0026plusmn;\u0026thinsp;0.62 (23\u0026ndash;25); outer length\u0026thinsp;=\u0026thinsp;22\u0026thinsp;\u0026plusmn;\u0026thinsp;0.38 (21\u0026ndash;23); inner root length\u0026thinsp;=\u0026thinsp;8\u0026thinsp;\u0026plusmn;\u0026thinsp;0.41 (8\u0026ndash;9); outer root length\u0026thinsp;=\u0026thinsp;4\u0026thinsp;\u0026plusmn;\u0026thinsp;0.5 (4\u0026ndash;5); point length\u0026thinsp;=\u0026thinsp;1\u0026thinsp;\u0026plusmn;\u0026thinsp;0.44 (1\u0026ndash;2). Thick and curved ventral bar with a median loop. Total length\u0026thinsp;=\u0026thinsp;19\u0026thinsp;\u0026plusmn;\u0026thinsp;1.05 (18\u0026ndash;21); total width\u0026thinsp;=\u0026thinsp;11\u0026thinsp;\u0026plusmn;\u0026thinsp;2.06 (7\u0026ndash;13); median width\u0026thinsp;=\u0026thinsp;5\u0026thinsp;\u0026plusmn;\u0026thinsp;1.03 (4\u0026ndash;6); diameter of the loop\u0026thinsp;=\u0026thinsp;2\u0026thinsp;\u0026plusmn;\u0026thinsp;0.23 (1\u0026ndash;2). Dorsal bar in the shape of \u003cb\u003eA\u003c/b\u003e letter. Total length\u0026thinsp;=\u0026thinsp;17\u0026thinsp;\u0026plusmn;\u0026thinsp;0.65 (15\u0026ndash;17); length of the large bar =\u0026thinsp;10\u0026thinsp;\u0026plusmn;\u0026thinsp;0.91 (8\u0026ndash;11); length of the small bar =\u0026thinsp;7\u0026thinsp;\u0026plusmn;\u0026thinsp;4.95 (6\u0026ndash;8); total width\u0026thinsp;=\u0026thinsp;13\u0026thinsp;\u0026plusmn;\u0026thinsp;2.81 (7\u0026ndash;15); median width\u0026thinsp;=\u0026thinsp;8\u0026thinsp;\u0026plusmn;\u0026thinsp;1.71 (4\u0026ndash;9). Sturdy hooks with filament. Pair I\u0026thinsp;=\u0026thinsp;14\u0026thinsp;\u0026plusmn;\u0026thinsp;1.39 (10\u0026ndash;15); pair II\u0026thinsp;=\u0026thinsp;12\u0026thinsp;\u0026plusmn;\u0026thinsp;1.06 (11\u0026ndash;14); pair III\u0026thinsp;=\u0026thinsp;15\u0026thinsp;\u0026plusmn;\u0026thinsp;1.88 (11\u0026ndash;17); pair IV\u0026thinsp;=\u0026thinsp;16\u0026thinsp;\u0026plusmn;\u0026thinsp;0.59 (15\u0026ndash;17); pair V\u0026thinsp;=\u0026thinsp;18\u0026thinsp;\u0026plusmn;\u0026thinsp;0.91 (17\u0026ndash;19); pair VI\u0026thinsp;=\u0026thinsp;17\u0026thinsp;\u0026plusmn;\u0026thinsp;0.83 (15\u0026ndash;17); pair VII\u0026thinsp;=\u0026thinsp;17\u0026thinsp;\u0026plusmn;\u0026thinsp;0.83 (16\u0026ndash;18). The MCO with oval basal ampulla and copulatory tube which, after a slight undulation, slides between the two branches of the terminal part of the accessory piece. Total length\u0026thinsp;=\u0026thinsp;35\u0026thinsp;\u0026plusmn;\u0026thinsp;1.97 (32\u0026ndash;40); tube trace length\u0026thinsp;=\u0026thinsp;35\u0026thinsp;\u0026plusmn;\u0026thinsp;3.13 (31\u0026ndash;40); base length\u0026thinsp;=\u0026thinsp;5\u0026thinsp;\u0026plusmn;\u0026thinsp;0.31 (4\u0026ndash;5); base width\u0026thinsp;=\u0026thinsp;4\u0026thinsp;\u0026plusmn;\u0026thinsp;0.25 (4\u0026ndash;5). The vagina was not observed.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eRemarks\u003c/b\u003e\u003c/p\u003e\u003cp\u003eThe similarities observed in the sclerotized parts of the haptor and the male copulatory organ allow us to link the specimens of the present parasite to the species \u003cem\u003eAnnulotrema nyongensis\u003c/em\u003e Birgi, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e1988\u003c/span\u003e, an ectoparasite of \u003cem\u003eB. kingsleyae\u003c/em\u003e. However, the measurements of the specimens obtained during the present study are smaller than those of the original description (355 vs 500). Furthermore, Birgi does not mention the loop observed at the level of the ventral transverse bar of all the specimens but a slight swelling.\u003c/p\u003e\u003cp\u003e\u003cb\u003eAnnulotrema amieti\u003c/b\u003e Birgi, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e1988\u003c/span\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eType host\u003c/b\u003e: \u003cb\u003ePhenacogrammus major\u003c/b\u003e \u003cb\u003eBoulenger, 1903\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eType locality: Nyong Basin in Yaound\u0026eacute; and Dja Basin in Sangm\u0026eacute;lima\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eOther localities: Akono River in Bingu\u0026eacute;la (3\u0026deg;42' 8''N; 11\u0026deg;37' 57''E)\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eInfestation site: Gills\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003ePrevalence: 80% (40 parasitized fish out of 50 fish examined)\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eNumber of individuals examined: 10 mounted in Malmberg liquid\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eType specimen: Paratype MNHN HEL 2081\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eRedescription (\u003c/b\u003eFig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e\u003cb\u003e)\u003c/b\u003e\u003c/p\u003e\u003cp\u003eBody length 604\u0026thinsp;\u0026plusmn;\u0026thinsp;207.33 (304\u0026ndash;763); width at pharynx 58\u0026thinsp;\u0026plusmn;\u0026thinsp;17.64 (36\u0026ndash;79); width at ovaries 66\u0026thinsp;\u0026plusmn;\u0026thinsp;17.13 (46\u0026ndash;87) and haptor width 85\u0026thinsp;\u0026plusmn;\u0026thinsp;19.79 (72\u0026ndash;114). Ventral anchors with well-individualized inner root and outer root. The blade is arched and the point is developed. Inner length\u0026thinsp;=\u0026thinsp;33\u0026thinsp;\u0026plusmn;\u0026thinsp;1.40 (31\u0026ndash;35); outer length\u0026thinsp;=\u0026thinsp;32\u0026thinsp;\u0026plusmn;\u0026thinsp;1.92 (30\u0026ndash;35); inner root length\u0026thinsp;=\u0026thinsp;11\u0026thinsp;\u0026plusmn;\u0026thinsp;0.98 (9\u0026ndash;13); outer root length\u0026thinsp;=\u0026thinsp;7\u0026thinsp;\u0026plusmn;\u0026thinsp;0.79 (6\u0026ndash;9); point length\u0026thinsp;=\u0026thinsp;4\u0026thinsp;\u0026plusmn;\u0026thinsp;0.40 (3\u0026ndash;4). Dorsal anchors with well-individualized inner root and thicker outer root in its basal part. Arched blade with long point. Inner length\u0026thinsp;=\u0026thinsp;32\u0026thinsp;\u0026plusmn;\u0026thinsp;3.0 (28\u0026ndash;35); outer length\u0026thinsp;=\u0026thinsp;32\u0026thinsp;\u0026plusmn;\u0026thinsp;3.02 (26\u0026ndash;35); inner root length\u0026thinsp;=\u0026thinsp;10\u0026thinsp;\u0026plusmn;\u0026thinsp;1.40 (9\u0026ndash;13); outer root length\u0026thinsp;=\u0026thinsp;6\u0026thinsp;\u0026plusmn;\u0026thinsp;1.07 (5\u0026ndash;8) and point length\u0026thinsp;=\u0026thinsp;4\u0026thinsp;\u0026plusmn;\u0026thinsp;0.72 (3\u0026ndash;5). Ventral bar with median expansion that then divides into two obliquely curved branches to reach the base by means of fine filaments. Total length\u0026thinsp;=\u0026thinsp;24\u0026thinsp;\u0026plusmn;\u0026thinsp;2.30 (21\u0026ndash;26), total width\u0026thinsp;=\u0026thinsp;13\u0026thinsp;\u0026plusmn;\u0026thinsp;2.59 (10\u0026ndash;18); median width\u0026thinsp;=\u0026thinsp;4\u0026thinsp;\u0026plusmn;\u0026thinsp;0.76 (3\u0026ndash;5). Triangular dorsal bar, concave and longer on the anterior side. Total length\u0026thinsp;=\u0026thinsp;23\u0026thinsp;\u0026plusmn;\u0026thinsp;2.0 (20\u0026ndash;27); Total width\u0026thinsp;=\u0026thinsp;11\u0026thinsp;\u0026plusmn;\u0026thinsp;1.4 (9\u0026ndash;13); median width\u0026thinsp;=\u0026thinsp;7\u0026thinsp;\u0026plusmn;\u0026thinsp;1.09 (4\u0026ndash;8). The hooks are dissimilar with pairs III to VII provided with filaments. Pair I\u0026thinsp;=\u0026thinsp;14\u0026thinsp;\u0026plusmn;\u0026thinsp;0.99 (13\u0026ndash;15); pair II\u0026thinsp;=\u0026thinsp;12\u0026thinsp;\u0026plusmn;\u0026thinsp;0.78 (11\u0026ndash;14); pair III\u0026thinsp;=\u0026thinsp;19\u0026thinsp;\u0026plusmn;\u0026thinsp;2.3 (16\u0026ndash;23); pair IV\u0026thinsp;=\u0026thinsp;21\u0026thinsp;\u0026plusmn;\u0026thinsp;2.26 (17\u0026ndash;24); pair V\u0026thinsp;=\u0026thinsp;25\u0026thinsp;\u0026plusmn;\u0026thinsp;3.9 (17\u0026ndash;29); pair VI\u0026thinsp;=\u0026thinsp;19\u0026thinsp;\u0026plusmn;\u0026thinsp;3.24 (14\u0026ndash;25); pair VII\u0026thinsp;=\u0026thinsp;22\u0026thinsp;\u0026plusmn;\u0026thinsp;1.47 (19\u0026ndash;24). The MCO with an oval basal ampulla and copulatory tube forms a clockwise turn, slides into the middle part of the accessory part and emerges towards its terminal part. Accessory part hook-shaped. Total length\u0026thinsp;=\u0026thinsp;19\u0026thinsp;\u0026plusmn;\u0026thinsp;2.33 (16\u0026ndash;22); tube trace length\u0026thinsp;=\u0026thinsp;56\u0026thinsp;\u0026plusmn;\u0026thinsp;4.06 (49\u0026ndash;61); base length\u0026thinsp;=\u0026thinsp;6\u0026thinsp;\u0026plusmn;\u0026thinsp;1.29 (4\u0026ndash;7); base width\u0026thinsp;=\u0026thinsp;5\u0026thinsp;\u0026plusmn;\u0026thinsp;0.8 (4\u0026ndash;7). The vagina tubular and thin. Total length\u0026thinsp;=\u0026thinsp;37.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eRemarks\u003c/b\u003e\u003c/p\u003e\u003cp\u003eThe haptor armature and the morphology of the MCO of the specimens obtained during our work are closer of those of \u003cem\u003eAnnulotrema amieti\u003c/em\u003e Birgi, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e1988\u003c/span\u003e described in Cameroon on the gills of \u003cem\u003eP. major\u003c/em\u003e. Despite some size differences observed at the level of the ventral hooks and transverse bars, the dimensions of the other sclerotized parts recorded by the two studies remain very similar. In addition, the presence of these parasites in the same host species leads us to associate them with the species \u003cem\u003eAnnulotrema amieti\u003c/em\u003e.\u003c/p\u003e\u003cp\u003e\u003cb\u003eAnnulotrema gabrioni\u003c/b\u003e Birgi, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e1988\u003c/span\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eType host\u003c/b\u003e: \u003cb\u003ePhenacogrammus major\u003c/b\u003e \u003cb\u003eBoulenger, 1903\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eType locality: Nyong Basin in Yaound\u0026eacute; and Dja Basin in Sangm\u0026eacute;lima\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eOther localities: Akono River in Bingu\u0026eacute;la (3\u0026deg;42' 8''N; 11\u0026deg;37' 57''E)\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eInfestation site: Gills\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003ePrevalence: 50% (25 parasitized fish out of 50 fish examined)\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eNumber of individuals examined: 10 mounted in Malmberg fluid\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eType specimen: Paratype MNHN HEL 2082\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eRedescription (\u003c/b\u003eFig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e7\u003c/span\u003e\u003cb\u003e)\u003c/b\u003e\u003c/p\u003e\u003cp\u003eBody length 373\u0026thinsp;\u0026plusmn;\u0026thinsp;68.81 (302\u0026ndash;519); width at pharynx 47\u0026thinsp;\u0026plusmn;\u0026thinsp;16.07 (13\u0026ndash;64); width at ovaries 64\u0026thinsp;\u0026plusmn;\u0026thinsp;16.46 (28\u0026ndash;85) and haptor width 63\u0026thinsp;\u0026plusmn;\u0026thinsp;11.23 (50\u0026ndash;87). Ventral anchors with robust inner root, well-arched blade and short point. Inner length\u0026thinsp;=\u0026thinsp;23\u0026thinsp;\u0026plusmn;\u0026thinsp;0.98 (22\u0026ndash;25); outer length\u0026thinsp;=\u0026thinsp;26\u0026thinsp;\u0026plusmn;\u0026thinsp;0.78 (25\u0026ndash;27); inner root length\u0026thinsp;=\u0026thinsp;8\u0026thinsp;\u0026plusmn;\u0026thinsp;1.04 (7\u0026ndash;10); outer root length\u0026thinsp;=\u0026thinsp;4\u0026thinsp;\u0026plusmn;\u0026thinsp;1.64 (2\u0026ndash;7); point length\u0026thinsp;=\u0026thinsp;1\u0026thinsp;\u0026plusmn;\u0026thinsp;0.35 (1\u0026ndash;2). Dorsal anchors less robust than the ventral ones, with well-developed inner root and outer root. Thin, slightly arched blade and long point. Inner length\u0026thinsp;=\u0026thinsp;26\u0026thinsp;\u0026plusmn;\u0026thinsp;0.69 (26\u0026ndash;27); outer length\u0026thinsp;=\u0026thinsp;26\u0026thinsp;\u0026plusmn;\u0026thinsp;1.6 (23\u0026ndash;29); inner root length\u0026thinsp;=\u0026thinsp;9\u0026thinsp;\u0026plusmn;\u0026thinsp;1.37 (7\u0026ndash;11); outer root length\u0026thinsp;=\u0026thinsp;5\u0026thinsp;\u0026plusmn;\u0026thinsp;1.29 (3\u0026ndash;7); point length\u0026thinsp;=\u0026thinsp;2\u0026thinsp;\u0026plusmn;\u0026thinsp;0.59 (1\u0026ndash;3). Arched ventral bar. Total length\u0026thinsp;=\u0026thinsp;19\u0026thinsp;\u0026plusmn;\u0026thinsp;1.6 (17\u0026ndash;22); total width\u0026thinsp;=\u0026thinsp;10\u0026thinsp;\u0026plusmn;\u0026thinsp;0.95 (9\u0026ndash;12); median width\u0026thinsp;=\u0026thinsp;4\u0026thinsp;\u0026plusmn;\u0026thinsp;0.93 (3\u0026ndash;7). Dorsal bar with the appearance of the letter A. Total length\u0026thinsp;=\u0026thinsp;16\u0026thinsp;\u0026plusmn;\u0026thinsp;1.0 (15\u0026ndash;19); total width\u0026thinsp;=\u0026thinsp;16\u0026thinsp;\u0026plusmn;\u0026thinsp;1.78 (12\u0026ndash;19); median width\u0026thinsp;=\u0026thinsp;6\u0026thinsp;\u0026plusmn;\u0026thinsp;0.67 (5\u0026ndash;7); opening diameter\u0026thinsp;=\u0026thinsp;6\u0026thinsp;\u0026plusmn;\u0026thinsp;0.67 (5\u0026ndash;7). Dissimilar hooks. Pair I\u0026thinsp;=\u0026thinsp;13\u0026thinsp;\u0026plusmn;\u0026thinsp;1.33 (12\u0026ndash;16); pair II\u0026thinsp;=\u0026thinsp;11\u0026thinsp;\u0026plusmn;\u0026thinsp;1.30 (9\u0026ndash;14); pair III\u0026thinsp;=\u0026thinsp;14\u0026thinsp;\u0026plusmn;\u0026thinsp;0.80 (13\u0026ndash;15); pair IV\u0026thinsp;=\u0026thinsp;14\u0026thinsp;\u0026plusmn;\u0026thinsp;1.58 (12\u0026ndash;18); pair V\u0026thinsp;=\u0026thinsp;18\u0026thinsp;\u0026plusmn;\u0026thinsp;1.86 (13\u0026ndash;19); pair VI\u0026thinsp;=\u0026thinsp;15\u0026thinsp;\u0026plusmn;\u0026thinsp;1.09 (13\u0026ndash;17); pair VII\u0026thinsp;=\u0026thinsp;15\u0026thinsp;\u0026plusmn;\u0026thinsp;1.01 (14\u0026ndash;16). The MCO begins with an oval basal bulb, fused to the base of the accessory part. The copulatory tube is short and insinuates itself into the accessory part and then comes out. The accessory part splits in its basal part to form a cap in the distal part. Total length\u0026thinsp;=\u0026thinsp;19\u0026thinsp;\u0026plusmn;\u0026thinsp;1.51 (16\u0026ndash;21); tube trace length\u0026thinsp;=\u0026thinsp;19\u0026thinsp;\u0026plusmn;\u0026thinsp;1.61 (16\u0026ndash;21); base length\u0026thinsp;=\u0026thinsp;5\u0026thinsp;\u0026plusmn;\u0026thinsp;0.67 (4\u0026ndash;6); base width\u0026thinsp;=\u0026thinsp;3\u0026thinsp;\u0026plusmn;\u0026thinsp;0.43 (3\u0026ndash;4). The vagina is 35 \u0026micro;m long. It begins with a flat, spatula-shaped base 4 \u0026micro;m long and 3 \u0026micro;m wide and continues with a tube 31 \u0026micro;m long.\u003c/p\u003e\u003cp\u003e\u003cb\u003eRemarks\u003c/b\u003e\u003c/p\u003e\u003cp\u003eThe structure and size of most of the parts of the haptor, as well as the morphology and measurements of the MCO of the specimens collected during the present work, lead us to assimilate them to \u003cem\u003eAnnulotrema gabrioni\u003c/em\u003e Birgi, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e1988\u003c/span\u003e. However, the triangular apophysis reported in the initial description on the ventral bar (Birgi, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e1988\u003c/span\u003e), was not observed during the analysis of our samples. Furthermore, Birgi does not report the sclerotization of the vagina. There are also differences in measurements at the level of the ventral and dorsal anchors (22\u0026ndash;25 vs 26\u0026ndash;30 and 26\u0026ndash;27 vs 30\u0026ndash;32 respectively).\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eAnnulotrema hepseti\u003c/b\u003e \u003cb\u003ePaperna and Thurston, 1969\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eType host\u003c/b\u003e: \u003cb\u003eHepsetus odoe\u003c/b\u003e \u003cb\u003e(Block, 1794)\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eType locality: Beira River in New Tafo (Ghana)\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eOther localities: Bia River at Ayam\u0026eacute; in Ivory Coast, Okavango River at Mohembo in Botswana, Dibamba River at Japoma in Cameroon (3\u0026deg;55' 31''N ; 9\u0026deg;40' 21''E)\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eInfestation site: Gills\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003ePrevalence: 100% (15 parasitized fish out of 15 fish examined)\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eNumber of individuals examined: 10 mounted in Malmberg liquid\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eType specimen: Paratype MNHN HEL 2084\u003c/b\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eRedescription (\u003c/b\u003eFig.\u0026nbsp;\u003cspan refid=\"Fig8\" class=\"InternalRef\"\u003e8\u003c/span\u003e\u003cb\u003e)\u003c/b\u003e\u003c/p\u003e\u003cp\u003eBody length 749\u0026thinsp;\u0026plusmn;\u0026thinsp;94.70 (549\u0026ndash;860); width at pharynx 97\u0026thinsp;\u0026plusmn;\u0026thinsp;18.91 (62\u0026ndash;128); width at ovaries 152\u0026thinsp;\u0026plusmn;\u0026thinsp;26.33 (107\u0026ndash;182) and haptor width 136\u0026thinsp;\u0026plusmn;\u0026thinsp;20.70 (109\u0026ndash;169). Ventral anchors with thick inner root, oblique blade and short point. Inner length\u0026thinsp;=\u0026thinsp;50\u0026thinsp;\u0026plusmn;\u0026thinsp;3.97 (41\u0026ndash;54); outer length\u0026thinsp;=\u0026thinsp;47\u0026thinsp;\u0026plusmn;\u0026thinsp;2.74 (40\u0026ndash;50); inner root length\u0026thinsp;=\u0026thinsp;20\u0026thinsp;\u0026plusmn;\u0026thinsp;1.69 (17\u0026ndash;24); outer root length\u0026thinsp;=\u0026thinsp;7\u0026thinsp;\u0026plusmn;\u0026thinsp;1.15 (5\u0026ndash;9); point length\u0026thinsp;=\u0026thinsp;4\u0026thinsp;\u0026plusmn;\u0026thinsp;0.9 (3\u0026ndash;6). Dorsal anchors with inner root three times longer than the outer root. Slightly arched blade and short point. Inner length\u0026thinsp;=\u0026thinsp;50\u0026thinsp;\u0026plusmn;\u0026thinsp;3.67 (41\u0026ndash;53); outer length\u0026thinsp;=\u0026thinsp;41\u0026thinsp;\u0026plusmn;\u0026thinsp;2.91 (34\u0026ndash;45); inner root length\u0026thinsp;=\u0026thinsp;19\u0026thinsp;\u0026plusmn;\u0026thinsp;2.26 (17\u0026ndash;24); outer root length\u0026thinsp;=\u0026thinsp;7\u0026thinsp;\u0026plusmn;\u0026thinsp;0.91 (5\u0026ndash;8); point length\u0026thinsp;=\u0026thinsp;4\u0026thinsp;\u0026plusmn;\u0026thinsp;0.68 (3\u0026ndash;5). Crescent-shaped ventral bar. Total length\u0026thinsp;=\u0026thinsp;34\u0026thinsp;\u0026plusmn;\u0026thinsp;4.01 (28\u0026ndash;43); total width\u0026thinsp;=\u0026thinsp;11\u0026thinsp;\u0026plusmn;\u0026thinsp;2.51 (7\u0026ndash;15); median width\u0026thinsp;=\u0026thinsp;7\u0026thinsp;\u0026plusmn;\u0026thinsp;1.26 (5\u0026ndash;8). Dorsal bar with crescent-shaped base, surmounted by a median rectangular sclerotization. Total length\u0026thinsp;=\u0026thinsp;28\u0026thinsp;\u0026plusmn;\u0026thinsp;2.55 (24\u0026ndash;32); Total width\u0026thinsp;=\u0026thinsp;11\u0026thinsp;\u0026plusmn;\u0026thinsp;1.75 (7\u0026ndash;12); Median width\u0026thinsp;=\u0026thinsp;7\u0026thinsp;\u0026plusmn;\u0026thinsp;1.67 (5\u0026ndash;10). Dissimilar hooks. Pair I\u0026thinsp;=\u0026thinsp;29\u0026thinsp;\u0026plusmn;\u0026thinsp;4.40 (18\u0026ndash;33); Pair II\u0026thinsp;=\u0026thinsp;13\u0026thinsp;\u0026plusmn;\u0026thinsp;1.92 (7\u0026ndash;14); Pair III\u0026thinsp;=\u0026thinsp;36\u0026thinsp;\u0026plusmn;\u0026thinsp;6.18 (20\u0026ndash;43); Pair IV\u0026thinsp;=\u0026thinsp;39\u0026thinsp;\u0026plusmn;\u0026thinsp;9.30 (18\u0026ndash;47); Pair V\u0026thinsp;=\u0026thinsp;37\u0026thinsp;\u0026plusmn;\u0026thinsp;6.09 (23\u0026ndash;45); Pair VI\u0026thinsp;=\u0026thinsp;35\u0026thinsp;\u0026plusmn;\u0026thinsp;6.98 (18\u0026ndash;41); Pair VII\u0026thinsp;=\u0026thinsp;33\u0026thinsp;\u0026plusmn;\u0026thinsp;5.12 (19\u0026ndash;37). The MCO is elongated with a pear-shaped basal ampulla. Copulatory tube with twists, distal accessory part forms a small capsule that covers the terminal part of the copulatory tube. Total length\u0026thinsp;=\u0026thinsp;65\u0026thinsp;\u0026plusmn;\u0026thinsp;7.91 (52\u0026ndash;76); tube trace length\u0026thinsp;=\u0026thinsp;56\u0026thinsp;\u0026plusmn;\u0026thinsp;7.80 (40\u0026ndash;66); base length\u0026thinsp;=\u0026thinsp;8\u0026thinsp;\u0026plusmn;\u0026thinsp;2.09 (6\u0026ndash;12); base width\u0026thinsp;=\u0026thinsp;5\u0026thinsp;\u0026plusmn;\u0026thinsp;0.6 (4\u0026ndash;6). The vagina is tubular ending in a fork. Total length\u0026thinsp;=\u0026thinsp;28\u0026thinsp;\u0026plusmn;\u0026thinsp;3.51 (24\u0026ndash;32).\u003c/p\u003e\u003cp\u003e\u003cb\u003eRemarks\u003c/b\u003e\u003c/p\u003e\u003cp\u003eThe morphology of the MCO is reminiscent of that of \u003cem\u003eAnnulotrema hepseti\u003c/em\u003e Paperna and Thurston, 1969, described in Ghana on the gills of \u003cem\u003eH. odoe\u003c/em\u003e. A redescription of this flatworm on the same host species was made in C\u0026ocirc;te d'Ivoire (N'Douba \u003cem\u003eet al\u003c/em\u003e., 1997) and Botswana (Christison, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e1998\u003c/span\u003e). Neither of these authors observed the membrane extension that we noted above the dorsal transverse bar. In addition, some measurements of the sclerotized parts of the haptor and copulatory apparatus obtained during the present study do not approach those of our predecessors. However, the great similarity observed in the morphology of the MCO and hooks allows us to link the samples examined to \u003cem\u003eA. hepseti\u003c/em\u003e.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\n\u003ch3\u003e3-2- Numerical phylogeny\u003c/h3\u003e\n\u003cp\u003eThe first of two principal component axes contributed respectively to 57.80% and 10.62% of the variation. Figure\u0026nbsp;\u003cspan refid=\"Fig9\" class=\"InternalRef\"\u003e9\u003c/span\u003e shows a graphical representation of the two first component coefficients for each variable. The principal component 1 was largely influenced by the measurements of hooks, VAI, VAO, VAIR, VAOR, DAI, DAO, DAIR, DAOR, VBW, DBH, whereas component 2 was mostly influenced by VAP and DAP. The projection of the individuals onto the factorial axes (Fig.\u0026nbsp;\u003cspan refid=\"Fig10\" class=\"InternalRef\"\u003e10\u003c/span\u003e) reveals that \u003cem\u003eA. nkengfacki\u003c/em\u003e is closer to the species of the \u003cem\u003eNyongensis\u003c/em\u003e group (red rectangle) with which it shares the same configuration of the MCO and bars. Specimen belonging to species \u003cem\u003eA. ngombiensis\u003c/em\u003e are highly divergent from all other species described in Cameroon (black rectangle), thus suggesting the creation of a new morphogroup that we propose to name \u003cem\u003eNgombiensis\u003c/em\u003e n. gr. A great variability of the specimens of \u003cem\u003eA. maillardi\u003c/em\u003e is highlighted, which may explain the morphological differences observed with the original morpho-description of Birgi (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e1988\u003c/span\u003e). The morphometric characters from the specimens of \u003cem\u003eA. combesi\u003c/em\u003e seem to bring it closer to the species of the \u003cem\u003eNyongensis\u003c/em\u003e morphogroup (\u003cem\u003eA. gabrioni\u003c/em\u003e and \u003cem\u003eA. nyongensis\u003c/em\u003e). A significant scattering is also detected among the individuals of \u003cem\u003eA. hepseti\u003c/em\u003e. The affinities between \u003cem\u003eA. bouixi\u003c/em\u003e, \u003cem\u003eA. amieti\u003c/em\u003e and \u003cem\u003eA. maillardi\u003c/em\u003e. However, \u003cem\u003eA. maillardi\u003c/em\u003e and \u003cem\u003eA. bouixi\u003c/em\u003e have more affinities with \u003cem\u003eA. hepseti\u003c/em\u003e, which is not the case of \u003cem\u003eA. amieti\u003c/em\u003e (the circle).\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003c/p\u003e"},{"header":"4- Discussion","content":"\u003cp\u003eThis work highlights new criteria for the diagnosis of some \u003cem\u003eAnnulotrema\u003c/em\u003e from Cameroon. The large discrepancies observed between the descriptions of Birgi (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e1988\u003c/span\u003e) and our redescriptions on \u003cem\u003eA. maillardi\u003c/em\u003e and \u003cem\u003eA. combesi\u003c/em\u003e could have several origins according to the literature. First, the difference in the quality of the samples as stipulated by Kičinjaov\u0026aacute; et al. (\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2015\u003c/span\u003e) during the redescription of \u003cem\u003eAnnulotrema elongata\u003c/em\u003e Paperna and Thurston, 1969. Also, we have the mounting techniques used which would influence the visibility of certain parts to the detriment of others (Řehulkov\u0026aacute; et al., \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e2014\u003c/span\u003e), thus explaining the differences in the representations of certain pieces and the non-observation of other ones. This last argument, cannot however be valid in our case because the preparations were made in both studies following similar protocols. We then side with Bilong Bilong (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e1995\u003c/span\u003e) and suggest the existence of morphological variability in time and space occupied by the host in monogeneans resulting from the influence of certain biotic and abiotic factors such as host size, climate or water quality. Numerical phylogeny was used for the first time to group \u003cem\u003eAnnulotrema\u003c/em\u003e. It thus confirmed some of the observations from the morphological studies made by Birgi (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e1988\u003c/span\u003e); firstly by supporting the criteria for creating the different morphogroups of \u003cem\u003eAnnulotrema\u003c/em\u003e in Cameroon, and also by stipulating the need to create a new morphogroup to classify \u003cem\u003eA. ngombiensis\u003c/em\u003e. Indeed, this species has an MCO whose configuration is far from all those listed on \u003cem\u003eAnnulotrema\u003c/em\u003e in Cameroon but this configuration of the MCO is rather close to that of \u003cem\u003eAnnulotrema\u003c/em\u003e parasitizing fishes of the genus \u003cem\u003eHydrocynus\u003c/em\u003e of West and East Africa. Multivariate analysis are however widely used to make affiliations among monogeneans of the same genus. This is for example the case of Bahanak et al. (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2022\u003c/span\u003e) on monogeneans of the genus \u003cem\u003eQuadriacanthus\u003c/em\u003e in Cameroon. Indeed, these authors used a PCA analysis to confirm that the morphometric parameters used for the description of \u003cem\u003eQuadriacantus barombiensis\u003c/em\u003e Bahanak, Nack and Pariselle, 2022 parasitic of \u003cem\u003eClarias maclareni\u003c/em\u003e Trewavas, 1962 were sufficient to separate this monogenean from its other congeners of Lake Barombi Mbo. Bahanak (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2018\u003c/span\u003e) used a similar approach to create three groups within the fish-parasitic monogeneans of the genus \u003cem\u003eQuadriacanthus\u003c/em\u003e in the family Clariidae, to confirm morphological observations made on the anchors and cunei of these monogeneans. Other authors have also used PCA to identify relationships between several species of monogeneans belonging to the same genus (Mariniello et al., 2003; Sarabeev and Balbuena, \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e2004\u003c/span\u003e; Rubtsova et al., \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e2006\u003c/span\u003e; Mulega et al., \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e2022\u003c/span\u003e).\u003c/p\u003e"},{"header":"5- Conclusion","content":"\u003cp\u003eThis work shows that the data collected during the work of Birgi (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e1988\u003c/span\u003e) are sometimes very far from the current ones. Hence the need to provide new type slides to facilitate diagnoses. The morphological analyses retained are sufficient to discriminate the species of monogeneans of the genus \u003cem\u003eAnnulotrema\u003c/em\u003e. However, the distance of the individuals of certain species revealed during the PCA analysis could suggest a genetic separation (or a speciation phenomenon) verifiable with molecular tools. However, the almost non-existence of molecular data on the monogeneans of the genus \u003cem\u003eAnnulotrema\u003c/em\u003e shows that only numerical phylogeny allows today to study the links between this group of monogeneans especially with regard to less developed countries.\u003c/p\u003e"},{"header":"Statements and declarations ","content":"\u003cp\u003e\u003cstrong\u003eCompeting of interests:\u0026nbsp;\u003c/strong\u003eThe authors declare that they have no conflict of interest.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthical approval:\u0026nbsp;\u003c/strong\u003eAll procedures involving animals were permitted and were strictly according to the rules of the committee for Animal and Human Bioethics (Ethical clearance Reference N\u0026deg;: BTC-JIRB2022-026)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements:\u0026nbsp;\u003c/strong\u003eWe thank the Professor Jean-Lou Justine of the National Museum of Natural History of Paris for his help in the conservation of type specimens.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFund\u003c/strong\u003e: No funding was received for the completion of this project.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contributions\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by NDONGO Ivan, TOMBI Jeannette, ONANA NGONO Michel Thierry, AKOUMBA John Francis and FOMENA Abraham. The first draft of the manuscript was made by NDONGO Ivan and all authors read and approved the final manuscript.\u0026nbsp;\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n \u003cli\u003eBahanak, D. N. D. (2018). \u003cem\u003eSyst\u0026eacute;matique, phylog\u0026eacute;nie, biog\u0026eacute;ographie et origine des Monog\u0026egrave;nes parasites des Clariidae du Cameroun\u003c/em\u003e. Th\u0026egrave;se Universit\u0026eacute; de Yaound\u0026eacute; I, 187p.\u003c/li\u003e\n \u003cli\u003eBahanak, D.N.D., Nack, J., Mbondo, J.A., Bassock Bayiha, E.D., Pariselle, A., Bilong Bilong, C.F. \u0026amp; Agn\u0026egrave;se, J.F. (2022). Description of a new species from \u003cem\u003eClarias maclareni\u003c/em\u003e and phylogenetical analysis of \u003cem\u003eQuadriacanthus\u003c/em\u003e (Monogenea, Dactylogyridae) species transfers between clariid and non-clariid fish hosts in Cameroon. \u003cem\u003eParasite\u003c/em\u003e, \u003cem\u003e29\u003c/em\u003e(37), 1-12. https://doi.org/10.1051/parasite/2022035\u003c/li\u003e\n \u003cli\u003eBates, J.W. (1997). The slide-sealing compound \u0026ldquo;Glyceel\u0026rdquo;. \u003cem\u003eJournal of Nematolology\u003c/em\u003e, \u003cem\u003e29\u003c/em\u003e, 565-566.\u003c/li\u003e\n \u003cli\u003eBilong Bilong, C.F. (1995). \u003cem\u003eLes 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; Hemichromis fasciatus\u003c/em\u003e. Th\u0026egrave;se de Doctorat d\u0026rsquo;Etat, Universit\u0026eacute; de Yaound\u0026eacute; I, 341p.\u003c/li\u003e\n \u003cli\u003eBirgi, E. (1988). Les monog\u0026egrave;nes de Characoidea de la zone foresti\u0026egrave;re Camerounaise. \u003cem\u003eAnnales de la Facult\u0026eacute; des Sciences Biologique et Biochimique\u003c/em\u003e,\u003cem\u003e\u0026nbsp;3\u003c/em\u003e(5), 59-111.\u003c/li\u003e\n \u003cli\u003eBrummett, R. E., Nguenga, D., Tiotsop, F. \u0026amp; Abina, J.C. (2010).The commercial fishery of the midle Nyong River, Cameroon productivity and environmental threats. \u003cem\u003eSmithiana\u0026nbsp;\u003c/em\u003e\u003cem\u003eBulletin\u003c/em\u003e,\u003cem\u003e\u0026nbsp;11\u003c/em\u003e, 3-16.\u003c/li\u003e\n \u003cli\u003eBuchmann, K. \u0026amp; Lindenstrom, T. (2002). Interactions between monogenean parasites and their fish hosts. \u003cem\u003eInternational Journal for Parasitology\u003c/em\u003e, \u003cem\u003e32\u003c/em\u003e, 309-319. https://doi.org/10.1016/S0020-7519(01)00332-0\u003c/li\u003e\n \u003cli\u003eChristison, K.W. (1998). \u003cem\u003eBranchial monogenean parasites (Monogenea: Dactylogyridae) of characin fishes from the Okavango river and Delta, Botswana\u003c/em\u003e. Thesis (M. Sc.) University of the Orange Free State, 251p.\u003c/li\u003e\n \u003cli\u003eEuzet, L. \u0026amp; Prost, M. (1981). Report of the meeting on Monogenea: Systematics, biology and ecology. In: Slusarski (Ed.), \u003cem\u003eReview of advances in parasitology Warsawa PWN. Polish Scientific Publishers\u003c/em\u003e, 1p.\u003c/li\u003e\n \u003cli\u003eKičinjaov\u0026aacute;, M.L., Blažek, R., Gelnar, M. \u0026amp; Řehulkov\u0026aacute;, E. (2015). \u003cem\u003eAnnulotrema\u003c/em\u003e (Monogenea: Dactylogyridae) from the gills of African tetras (Characiformes: Alestidae) in Lake Turkana, Kenya, with descriptions of four new species and a redescription of \u003cem\u003eA. elongata\u003c/em\u003e Paperna and Thurston, 1969. \u003cem\u003eParasitology Research\u003c/em\u003e, \u003cem\u003e114\u003c/em\u003e, 4107-4120. https://doi.org/10.1007/s00436-015-4682-x\u003c/li\u003e\n \u003cli\u003eKičinjaov\u0026aacute;, M.L., Přikrylov\u0026aacute;, I., Seifertov\u0026aacute;, M., Řehulkov\u0026aacute;, E., Gelnar, M \u0026amp; Smit, N. J. (2024). \u003cem\u003eAnnulotrema\u003c/em\u003e species (Monopisthocotylea, Dactylogyridae) parasiting African tetras (Characiformes, Alestidae) in the Phongolo River, South Africa with the description of four new species. \u003cem\u003eParasite, 31\u003c/em\u003e(67), 1-14. http://doi.org/10.1051/parasite/2024066\u003c/li\u003e\n \u003cli\u003eMalmberg, G. (1957). On the occurrence of \u003cem\u003eGyrodactylus\u003c/em\u003e on Swedish fishes. \u003cem\u003eSkrifterutgitiva av S\u0026ouml;dra Sveriges Fiskerif\u0026ouml;rening\u003c/em\u003e, (1956), 19-76.\u003c/li\u003e\n \u003cli\u003eMarinello, L., Ortis, M., D\u0026rsquo;Amelio, S. \u0026amp; Petrarca, V. (2004). Morphometric variability between and within species of \u003cem\u003eLigophorus\u003c/em\u003e Euzet \u0026amp;Suriano, 1977 (Monogenea: Ancyrocephalidae) in the Mediterranean Sea. \u003cem\u003eSystematic Parasitology\u003c/em\u003e, \u003cem\u003e57\u003c/em\u003e, 183-190. https://doi.org/10.1023/B:SYPA.0000019080.43784.06\u003c/li\u003e\n \u003cli\u003eMulega, M. F., Bukinga, F.M., Akoumba, J.F., Mulungula, P.M. \u0026amp; Pariselle, A. (2022). Monogeneans from Catfishes in Lake Tanganyika. I: Two new species of \u003cem\u003eBagrobdella\u0026nbsp;\u003c/em\u003e(Dactylogyridae) from \u003cem\u003eAuchenoglanis occidentatlis\u003c/em\u003e (Siluriformes: Claroteidae). \u003cem\u003eZoologia\u003c/em\u003e, (39), 13p. https://doi.org./10.1590/s1984-4689.v39.e22016\u003c/li\u003e\n \u003cli\u003eNdongo, I. (2025). \u003cem\u003eFaunistique 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 Littoral, Cameroun\u003c/em\u003e. Th\u0026egrave;se de Doctorat/PhD, Universit\u0026eacute; de Yaound\u0026eacute; I. 185p.\u003c/li\u003e\n \u003cli\u003eNdongo, I., Akoumba, J.F., Tombi, J., Morand, S. \u0026amp; Fomena, A. (2023). Two new species of Annulotrema (Monogenea: Dactylogyridae) gill parasites of Brycinus macrolepidotus Valenciennes, 1849 from Nyong River, Cameroon. \u003cem\u003eActa Parasitologica\u003c/em\u003e, (68), 257-265. https://doi.org/10.1007/s11686-022-00645-y\u003c/li\u003e\n \u003cli\u003eŘehulkov\u0026aacute;, E., Kičinjaov\u0026aacute;, M.L., Mahmoud, Z.N., Gelnar, M. \u0026amp; Seifertov\u0026aacute;, M. (2019).Species of \u003cem\u003eCharacidotrema\u003c/em\u003e Paperna \u0026amp; Thurston 1968 (Monogenea: Dactylogyridae) from fishes of the Alestidae (Characiformes) in Africa: new species, host-parasite associations and first insights into the phylogeny of the genus. \u003cem\u003eParasite \u0026amp; Vectors\u003c/em\u003e, \u003cem\u003e12\u003c/em\u003e (1), 1-21. https://doi.org/10.1186/s13071-019-3580-y\u003c/li\u003e\n \u003cli\u003eŘehulkov\u0026aacute;, E., Musilov\u0026aacute;, N. \u0026amp; Gelnar, M. (2014). \u003cem\u003eAnnulotrema\u003c/em\u003e (Monogenea: Dactylogyridae) from \u003cem\u003eHydrocynus brevis\u003c/em\u003e (Characiformes: Alestidae) in Senegal, with descriptions of two new species and remarks on \u003cem\u003eAnnulotrema pikei\u003c/em\u003e. \u003cem\u003eParasitology Research\u003c/em\u003e, \u003cem\u003e113\u003c/em\u003e (9), 3273 ̶ 3280. https://doi.org/10.10007/s00436-014-3990-x\u003c/li\u003e\n \u003cli\u003eRubtsova, N.Y., Balbuena, J.A., Sarabeev, V.L., Blanco-Costa, I. \u0026amp; Euzet, L. (2006). Description and Morphometrical variability of a new species of \u003cem\u003eLigophorus\u003c/em\u003e and \u003cem\u003eLigophorus chabaudi\u003c/em\u003e (Monogenea: Dactylogyridae) on \u003cem\u003eMugil cephalus\u003c/em\u003e (Teleostei) from the Mediterranean Basin. \u003cem\u003eJournal for Parasitology\u003c/em\u003e, \u003cem\u003e92\u003c/em\u003e (3), 486-495. https://doi.org/10.16145/GE-747R.1\u003c/li\u003e\n \u003cli\u003eSarabeev, V.L. \u0026amp; Balbuena, J.A (2004). \u003cem\u003eLigophorus pilengas\u003c/em\u003e n. sp. (Monogenea: Ancyrocephalidae) from the introduced So-iuy Mullet, \u003cem\u003eMugil soiuy\u003c/em\u003e (Teleostei:Mugilidae), in the Sea of Azov and Black Sea. \u003cem\u003eJournal of Parasitology\u003c/em\u003e, \u003cem\u003e90\u003c/em\u003e (2), 222-228. https://doi.org/10.1645/GE-163R\u003c/li\u003e\n \u003cli\u003eStiassny, M. L. J., Teugels, G. G. \u0026amp; Hopkins, C. D. (2007). \u003cem\u003ePoissons d\u0026rsquo;eaux douces et saum\u0026acirc;tres de basse Guin\u0026eacute;e, ouest de l\u0026rsquo;Afrique Centrale\u003c/em\u003e. Volume 1. Tervuren, Belgique. MRHC. IRD, \u003cem\u003eParis France Faune tropicale\u003c/em\u003e (42), 352-353.\u003c/li\u003e\n\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":"","lastPublishedDoi":"10.21203/rs.3.rs-7468163/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7468163/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThe study of the monogenean fauna of four Characiformes consumed in Cameroon has allowed the redescription of seven species of \u003cem\u003eAnnulotrema\u003c/em\u003ePaperna and Thurston, 1969 and has provided new information for the diagnosis of these helminths. Thus, concerning the parasites of \u003cem\u003eBrycinus kingsleyae\u003c/em\u003e Günther, 1986, in \u003cem\u003eAnnulotrema combesi\u003c/em\u003e Birgi, 1988, the copulatory tube can make two turns of spire contrary to the initial description which indicates a single turn; on the dorsal transverse bar of \u003cem\u003eAnulotrema maillardi\u003c/em\u003e Birgi, 1988, a sclerotized structure was observed for the first time; a loop was also noted for the first time on the ventral bar of \u003cem\u003eAnnulotrema nyongesnsis\u003c/em\u003e Birgi, 1988. For parasites of \u003cem\u003ePhenacogrammus major\u003c/em\u003e, the vagina was observed for the first time in \u003cem\u003eAnnulotrema gabrioni\u003c/em\u003e Birgi, 1988. A membrane extension never reported on the dorsal transverse bar of \u003cem\u003eAnnulotrema hepseti\u003c/em\u003e Paperna and Thurston, 1969, a parasite of \u003cem\u003eHepsetus odoe\u003c/em\u003e was observed during this study. Numerical phylogeny allowed the assignment of a morphogroup to the two newly described species in \u003cem\u003eBrycinus macrolepidotus\u003c/em\u003e Valenciennes, 1849. Thus, a new morphologroup named \u003cem\u003eNgombiensis\u003c/em\u003en. gr. was created to classify \u003cem\u003eAnnulotrema ngombiensis\u003c/em\u003e Ndongo and Tombi, 2023. As for \u003cem\u003eAnnulotrema nkengfacki\u003c/em\u003e Ndongo and Tombi, 2023, its morphometric characteristics allow it to be associated with the \u003cem\u003eNyongensis\u003c/em\u003e group created by Birgi in 1988.\u003c/p\u003e","manuscriptTitle":"Integrative taxonomy of Annulotrema (Monogenea: Dactylogyridae) from some Characiformes of Cameroon: Redescriptions and morphogroup delimitation using numerical phylogeny","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-09-08 09:37:08","doi":"10.21203/rs.3.rs-7468163/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-12-12T19:53:51+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-10-23T15:36:38+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"336182117118142496540849146992378751177","date":"2025-09-20T21:30:12+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-09-02T11:03:00+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-08-28T01:41:35+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-08-28T01:39:23+00:00","index":"","fulltext":""},{"type":"submitted","content":"Systematic Parasitology","date":"2025-08-27T05:52:13+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":"3bc2b2fa-01ee-4efc-b11b-54b5c53d8df6","owner":[],"postedDate":"September 8th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2025-12-26T20:08:28+00:00","versionOfRecord":[],"versionCreatedAt":"2025-09-08 09:37:08","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7468163","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7468163","identity":"rs-7468163","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}