Myxobolus wondjii sp. nov. (Myxozoa: Myxobolidae), a parasite of Labeo batesii Boulenger, 1911 (Teleostei: Cyprinidae) from the Makombè River, Cameroon: Morphological and molecular characterization

1 European Journal of Taxonomy 1022: 1–18 https://doi.org/10.5852/ejt.2025.1022.3077 europeanjournaloftaxonomy.eu ISSN 2118-9773 2025 · Lekeufack-Folefack G.B. et al. This work is licensed under a Creative Commons Attribution License (CC BY 4.0) Received: 12 October 2024 • Accepted: 10 July 2025 • Published: 29 September 2025 Section editor: Peter Vďačný • Desk editor: Pepe Fernández Research article urn:lsid:zoobank.org:pub:E1DA282F-D967-43BF-9AA5-AFAF0C591BE6 Myxobolus wondjii sp. nov. (Myxozoa: Myxobolidae), a parasite of Labeo batesii Boulenger, 1911 (Teleostei: Cyprinidae) from the Makombè River, Cameroon: Morphological and molecular characterization Guy Benoît LEKEUFACK-FOLEFACK 1 , Bienvenu FEUDJIO-DONGMO 2 , Billy TENE-FOSSOG 3 , Murielle J. WONDJI 4 , Abraham FOMENA 5 , Violetta YURAKHNO 6 , Christopher M. WHIPPS 7 , Saleh ALQURASHY 8 & Lamjed MANSOUR 9,* 1,5 Laboratory of Parasitology and Ecology, Department of Animal Biology and Physiology, Faculty of Sciences, University of Yaoundé I, P.O. Box 812, Yaoundé, Cameroon. 2 Department of Life Science, Higher Teacher Training College, University of Bertoua, P.O. Box 652, Bertoua, Cameroon. 3,4 Centre for Research in Infectious Diseases, P.O. Box 13501, Yaoundé, Cameroon. 3,4 Vector Biology Department, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, United Kingdom. 6 A.O. Kovalevsky Institute of Biology of the Southern Seas, Russian Academy of Sciences, 2 Nakhimov Av., 299011, Sevastopol, Russian Federation. 7 College of Environmental Science and Forestry, Environmental Biology, State University of New York, 1 Forestry Drive, Syracuse, New York 13210, United States. 8,9 Department of Zoology, College of Science, King Saud University, P.O. Box 2455, 11451 Riyadh, Saudi Arabia. * Corresponding author: [email protected] and [email protected] 1 Email: [email protected] 2 Email: [email protected] 3 Email: billy[email protected] 4 Email: [email protected] 5 Email: [email protected] 6 Email: [email protected] 7 Email: [email protected] 8 Email: [email protected] Abstract. A new species of the genus Myxobolus Bütschli, 1882 (Myxosporea: Bivalvulida) is described based on morphology, histopathology, and small subunit ribosomal DNA (SSU rDNA) sequence data. Myxobolus wondjii sp. nov. was found infecting the gills of Labeo batesii Boulenger, 1911 from the Makombè River at Nkondjock, Cameroon. Large, subspherical, whitish plasmodia measuring 100– 2000 µm in length and 60–1400 µm in width were observed. Histopathological examination revealed European Journal of Taxonomy 1022: 1–18 (2025) 2 plasmodia located in the interbranchial septum of the gill. Mature myxospores were ovoid, slightly tapering anteriorly, and with a broad, rounded posterior end. The myxospores measured 12.4 ± 0.1 (12.0–13.2) μm in length and 8.8 ± 0.07 (8.3–9.4) μm in width. The two polar capsules were ovoid and distinctly unequal in size, measuring 5.4 ± 0.50 (4.8–6.3) × 3.2 ± 0.06 (2.7–3.7) μm for the larger capsule and 1.6 ± 0.06 (1.4–1.7) × 1.0 ± 0.08 (0.9–1.1) μm for the smaller one. A partial SSU rDNA sequence was obtained from this new species, and phylogenetic analysis placed it as sister to Myxobolus nkondjockei, which also infects L. batesii in Cameroon. Keywords. Cyprinid fish, Africa, freshwater, fish parasites, Myxosporea, SSU rDNA. Lekeufack-Folefack G.B., Feudjio-Dongmo B., Tene-Fossog B., Wondji M.J., Fomena A., Yurakhno V., Whipps C.M., Alqurashy S. & Lamjed M. 2025. Myxobolus wondjii sp. nov. (Myxozoa: Myxobolidae), a parasite of Labeo batesii Boulenger, 1911 (Teleostei: Cyprinidae) from the Makombè River, Cameroon: Morphological and molecular characterization. European Journal of Taxonomy 1022: 1–18. https://doi.org/10.5852/ejt.2025.1022.3077 Introduction Myxozoans are a group of microscopic cnidarians that primarily parasitize fish, some of which are associated with host morbidity and mortality (Lom & Dyková 2006). In freshwater species where the life cycle is known, it involves two distinct stages: myxospores emerging from fish and actinospores from oligochaete worms. In marine environments, myxozoans typically utilize polychaete worms as invertebrate hosts (Okamura et al. 2015). Globally, over 2200 species of myxozoans have been classified into 64 genera and 17 families (Fiala et al. 2015). However, the known myxozoan fauna parasitizing freshwater fishes in Africa comprises only about 280 species. In Cameroon, more than 80 species have been reported, with half belonging to the genus Myxobolus Bütschli, 1882 (Deli et al. 2017). The genus Myxobolus includes more than 1027 described species, representing a large portion of known myxozoan diversity (Eiras et al. 2021). Infections by species of this genus are often histozoic, targeting the skin, muscles, gills, or digestive system (Eiras et al. 2005, 2014, 2021). Myxobolus myxospores are typically elliptoid, ovoid, or orbicular in valvular view, and biconvex in sutural view. The shell valves are usually smooth and enclose two pyriform polar capsules, which are sometimes unequal in size (Lom & Dyková 2006). Most myxozoan species are classified based solely on myxospore morphology (Fiala et al. 2015). However, due to similarities in shape and size among many species, morphology-based differentiation between congeners is often difficult and artificial (Molnár et al. 2010; Rocha et al. 2019; Mirandola Dias Vieira et al. 2022; Okkay et al. 2024). To address this limitation, many authors have advocated for the integration of phenotypic and genetic data to improve the identification and classification of myxozoans. Molecular methods, primarily based on small subunit ribosomal DNA (SSU rDNA) sequences, enable the differentiation of morphologically similar species (Kent et al. 2001; Ferguson et al. 2008; Guo et al. 2018) and facilitate the study of phylogenetic relationships, host specificity, and tissue tropism (Eszterbauer 2004; Fiala et al. 2015). In Africa, molecular and phylogenetic data on myxozoans remain limited. The few available records from sub-Saharan Africa include Myxobolus dibombensis Lekeufack-Folefack, Abdel-Baki, Ateba, Fomena & Mansour, 2019, M. opsaridiumi Lekeufack-Folefack, Tchoutezo-Tiwa, Fomena & Mansour, 2021, M. nkondjockei Lekeufack-Folefack, Feudjio-Dongmo, Tene-Fossog, Fomena, Wondji, Al-Tamimi, Yurakhno & Mansour, 2022 , and M. makombensis FeudjioDongmo, Lekeufack-Folefack, Tene-Fossog, Fomena, Wondji, Yurakhno & Mansour, 2022. This represents a promising area for future discovery, especially as DNA sequencing becomes more accessible and applicable to the likely high diversity of African myxozoans. LEKEUFACK-FOLEFACK G.B. et al., Myxobolus wondjii sp. nov. from Labeo batesii 3 Fishes of the genus Labeo Cuvier, 1817 are cyprinids classified within the subfamily Labeoninae Bleeker, 1859. They are distributed across Africa and Southeast Asia, where they are valued as important food fish (Howes 1991; Skelton et al. 1991). The Makombè River, a major tributary of the Wouri Basin in Cameroon, supports a rich ichthyofauna, including Labeo batesii Boulenger, 1911. This species is locally prized for its flavor and nutritional value, serving as a source of protein, trace elements, and polyunsaturated fatty acids (Ruxton et al. 2005; Feudjio-Dongmo 2023). Due to its reproductive capacity, rapid growth, and commercial potential, L. batesii is also considered a promising candidate for aquaculture (Ayoade et al. 2008; Nwani et al. 2011). However, as emphasized by Lekeufack-Folefack & Fomena (2013), understanding the parasite biodiversity of wild fish populations is essential for assessing potential health risks in aquaculture systems. The present study is part of an ongoing investigation aimed at characterizing myxozoan parasites in freshwater fishes of Cameroon. During this work, we identified a species of Myxobolus infecting the gill of L. batesii from the Makombè River. Based on tissue tropism, myxospore morphology and dimensions, and SSU rDNA sequence analysis, we propose that this organism represents a new species. Material and methods Fish sampling A total of 515 specimens of L. batesii, locally known as “mangy mouth”, were captured using gill nets between May 2017 and July 2018 in the Makombè River at Nkondjock, Littoral Region, Cameroon (4°42′49″−4°54′36″ N, 10°10′20″−10°15′41″ E). The harvested fish (standard length: 12.0–19.5 cm) were transported on ice to the Laboratory of Parasitology and Ecology at the University of Yaoundé I, Cameroon. Species identification was performed following Stiassny et al. (2007). Morphological and histological analysis External organs of L. batesii, including the eyes, operculum, scales, skin, and fins, were initially examined for the presence of plasmodia by direct observation and under an Olympus BO61 binocular stereoscopic microscope. Internal organs (kidney, bile duct, liver, gall bladder, digestive tract, spleen, heart, gonads, urinary duct, urethras, and muscles) were then dissected and examined under the same microscope. Smears from the kidney, spleen, liver, gonads, heart, and urethra were examined under a 40× objective using an IVYMEN light microscope. To assess the gill plasmodia index, the average number of plasmodia on one side of the gill was estimated. Infection intensity was categorized as light (1–5 plasmodia), moderate (6–10 plasmodia), heavy (11–20 plasmodia), or severe (21 or more plasmodia), following Kaur & Attri (2015). Fresh plasmodia were isolated for morphological and molecular analyses. Morphometric characterization of 50 mature myxospores was performed under a 100× objective using an IVYMEN light microscope, following Lom & Arthur (1989). Some smears were fixed in methanol and stained with May-GrünwaldGiemsa (Piaton et al. 2015). Both fresh and stained myxospores were photographed using an Olympus BH-2 microscope (Olympus Optical Co., Ltd, Tokyo, Japan) equipped with a digital camera. Histological sections were prepared from parasitized gill tissues. Infected gills were fixed in 10% neutral buffered formalin and processed using standard histological protocols as described by Wolfe (2019). Molecular characterization and phylogenetic analysis Genomic DNA was extracted from ethanol-preserved plasmodia using the optimized Livak protocol (Lekeufack-Folefack et al. 2020). A partial SSU rDNA sequence was amplified using the primers MC5 (5′-CCT GAG AAA CGG CTA CCA CAT CCA-3′) and MC3 (5′-GAT TAG CCT GAC AGA TCA CTC CAC GA-3′) (Molnár et al. 2002) in a Bioer Gene Touch Thermocycler (Dutscher). PCR reactions European Journal of Taxonomy 1022: 1–18 (2025) 4 were prepared in a 15 µl volume, containing 1.5 µl (50‒200 ng) of extracted DNA, 0.2 μM of each primer, and 7.5 µl of OneTaq ® Quick-Load ® 2X Master Mix (New England Biolabs, Canada). The amplification protocol consisted of an initial denaturation at 9°C for 5 min, followed by 35 cycles of 95°C for 60 s, 60°C for 60 s, and 72°C for 90 s, with a final extension at 72°C for 5 min (Adriano et al. 2012). PCR products were visualized by electrophoresis on a 1.5% agarose gel (3 μl aliquots), and the remaining product was purified using a QIAquick PCR Purification Kit (QIAGEN, USA) according to the manufacturer’s instructions. Sequencing was performed by Genewiz (Liverpool, United Kingdom) using the same primers. Forward and reverse sequences were assembled and edited in BioEdit ver. 7.1.8.0 (Hall 1999). Sequence similarity was assessed using the NCBI Basic Local Alignment Search Tool (BLASTn) (Altschul et al. 1997). Taxon selection for the phylogenetic analysis included 38 species of Myxobolus identified based on BLAST search results as closest relatives of Myxobolus wondjii sp. nov., along with four species from Cameroon (Lekeufack-Folefack et al. 2019, 2021, 2022; Feudjio-Dongmo et al. 2022). The sequence of Myxobilatus gasterostei Atkinson & Bartholomew, 2009 (GenBank accession number: EU861210) was used as an outgroup. Nucleotide sequences were aligned using ClustalW with default parameters in the BioEdit program (Hall 1999). The resulting alignment was trimmed in BioEdit and exported as FASTA and NEXUS files. The final dataset comprised 796 aligned nucleotide positions. Phylogenetic relationships were analyzed using Bayesian Inference (BI) and Maximum Likelihood (ML). BI analysis was conducted in MrBayes ver. 3.2 7 (Ronquist et al. 2012) for 3.5 million generations using a Markov Chain Monte Carlo (MCMC) algorithm with two independent runs, each consisting of four simultaneous chains (nchains = 4). Trees were sampled every 175 generations (samplefreq = 175), and the first 25% of trees from each run were discarded as burn-in to ensure sampling at stationarity. The remaining trees were used to estimate posterior probabilities for the nodes. ML analysis was performed using RAxML ver. 8.2.9 (Kozlov et al. 2019) via the online platform, with bootstrap support values calculated from 1000 pseudoreplicates. Both BI and ML analyses were conducted under the GTR + I + G model, selected using jModelTest ver. 2.1.10 (Darriba et al. 2012) based on the Akaike Information Criterion (AIC). Phylogenetic trees were visualized using FigTree ver. 1.4.3 (Rambaut 2016) and edited in Adobe Illustrator (Adobe Systems, San Jose, CA, USA). Abbreviations BI = Bayesian inference IBS = interbranchial septum ICA = intercapsular appendix IS = Immature myxospores LPC = length of polar capsules MCMC = Markov Chain Monte Carlo ML = maximum likelihood MS = mature myxospores P = plasmodium PC = relative length of the polar capsules PCR = polymerase chain reaction PT = number of coils of polar tubule SL = spore length SSU rDNA = small subunit ribosomal DNA SW = spore width WPC = width of polar capsules LEKEUFACK-FOLEFACK G.B. et al., Myxobolus wondjii sp. nov. from Labeo batesii 5 Results Systematic account Phylum Cnidaria Hatschek, 1888 Subphylum Myxozoa Grassé, 1970 Class Myxosporea Bütschli, 1881 Order Bivalvulida Shulman, 1959 Suborder Platysporina Kudo, 1919 Family Myxobolidae Thélohan, 1892 Genus Myxobolus Bütschli, 1882 Myxobolus wondjii sp. nov. urn:lsid:zoobank.org:act:8A6EF76D-A64D-4BFB-8814-74069C78D409 Figs 1‒2; Table 1 Diagnosis Myxospores 12.0–13.2 × 8.3–9.4 μm in size; ovoid, slightly tapering anteriorly and with a broad, rounded posterior end; polar capsules ovoid and markedly unequal in size: larger capsule 5.4 × 3.2 µm on average, containing a polar tubule coiled in 9 to 11 turns and occupying anterior half of myxospore cavity, while smaller capsule 1.6 × 1.0 µm on average, with no visible polar tubule and occupying approximately 1/10 of cavity length. Plasmodia large (100–2000 × 60–1400 µm), subspherical, whitish, and located in interbranchial septa of host gills. Etymology The specific epithet wondjii is given in honor of Wondji Charles Synclair, Professor at the Liverpool School of Tropical Medicine, United Kingdom. Type material Hapantotype CAMEROON • gills of Labeo batesii Boulenger, 1911 infected with plasmodia (in Eppendorf tubes (50 ml) containing formalin-fixed); Littoral Region, Nkondjock, Makombè River; 4°42′49″−4°54′36″ N, 10°10′20″−10°15′41″ E; GenBank no PQ407595; parasitological collection of the Laboratory of Parasitology and Ecology, Faculty of Sciences, University of Yaoundé I, Cameroon No. Myxo/2024/LPE002. Taxonomic summary Type locality Makombè River, Nkondjock, Littoral Region, Cameroon, 4°42′49″−4°54′36″ N, 10°10′20″−10°15′41″ E. Type host Labeo batesii Boulenger, 1911 (Cyprinidae). Site of infection Gill, interbranchial septum. Vegetative stages Large, whitish, subspherical plasmodia of variable size were observed on the gills of 66 out of 515 examined specimens of L. batesii, corresponding to a prevalence of 12.8% (Fig. 1a–b). These plasmodia measured 100–2000 µm in length and 60–1400 µm in width. Up to 27 plasmodia were found per parasitized fish, with infections present on both gill arches. Development appeared asynchronous, as indicated by the presence of plasmodia of various sizes (Fig. 1a). The gill plasmodia index (mean ± SD) European Journal of Taxonomy 1022: 1–18 (2025) 6 Fig. 1. Photomicrographs of gills of Labeo batesii Boulenger, 1911 showing plasmodia of Myxobolus wondjii sp. nov. A. Fresh preparation showing whitish plasmodia in the gills (arrowheads). B. Highmagnification fresh preparation showing a plasmodium (P) located on the interbranchial septum (IBS). C. Histological section of gills stained with H&E showing the general morphology of the plasmodium (P) in the interbranchial septum (IBS). D. Histological section stained with H&E showing cyst protrusions (arrowheads). E. Histological section stained with H&E showing: lack of adhesion between tissue layers surrounding the plasmodium; influx of monocytes at the plasmodium periphery (arrows); multilayered membrane surrounding the plasmodium; immature myxospores (IS) at the periphery and mature myxospores (MS) in the medial part of the plasmodium. Abbreviations: IBS = interbranchial septum; IS = immature myxospores; MS = mature myxospores; P = plasmodium. LEKEUFACK-FOLEFACK G.B. et al., Myxobolus wondjii sp. nov. from Labeo batesii 7 was 2.3 ± 0.6 (range: 1−8), indicating a light infection. Overall, the intensity of infection was classified as light. Description Histological examination Histological sections of the gills revealed that plasmodia were located in the connective tissue of the interbranchial septum (Fig. 1c). The plasmodia exhibited peripheral protrusions, likely resulting from modifications of the surrounding host tissues induced by their growth (Fig. 1d). At higher magnification (Fig. 1e), the parasitized tissue showed: (1) alteration and lack of adhesion between the tissue layers surrounding the plasmodium; (2) a multi-layered membrane enclosing the plasmodium, including an outer layer of collagen fibers; (3) presence of monocytes at the plasmodium periphery; and (4) immature myxospores in the peripheral zone and mature myxospores in the median zone of the plasmodium. Mature myxospores Myxospores were ovoid, slightly tapering anteriorly and with a broad, rounded posterior end (Fig. 2a). In sutural view, myxospores appeared biconvex (Fig. 2b). The valves were thick and smooth, with no apparent sutural ridge markings, though the suture line was prominent (Fig. 2b). Two apically oriented polar capsules were ovoid, markedly unequal in size and converging towards the apex of the myxospore (Fig. 2a, c–d). The large polar capsule was well developed (5.4 × 3.2 µm on average), containing a polar tubule coiled in 9 to 11 turns and occupying the anterior half of the myxospore cavity (Fig. 2d). The smaller polar capsule was extremely reduced (1.6 × 1.0 µm on average), occupying approximately 1/10of the cavity length, with no visible polar tubule (Fig. 2a, c–d). The remainder of the cavity was filled with sporoplasm, which contained an iodinophilous vacuole of variable size, shape, and position (Fig. 2a, d). Mean myxospore dimensions are provided in Table 1. Remarks A striking feature of M. wondjii sp. nov. is the extremely reduced second polar capsule. While not unique among species of Myxobolus, this trait is unusual (Lom & Dyková 2006). Through examination of species synopses (Eiras et al. 2005, 2014, 2021) and database searches of more recent articles, we identified 20 species of Myxobolus with distinctly unequal polar capsules. In some species (Myxobolus buccoroofus Basu & Haldar, 2004; M. harikensis Kaur & Singh, 2011; M. mrigalhitae Basu & Haldar, 2003; Myxobolus patialensis Kaur & Singh, 2011), the smaller polar capsule discharges away from the apex of the myxospore. In others, the smaller polar capsule discharges at the apex (M. andhrae (Lalitha Kumari, 1969); M. bhadrensis Seenappa & Manohar, 1981; M. chilkensis (Kalavati, Vankateswara Rao & Vaidahei, 1992); M. duodenalis Kaur & Singh, 2011; M. goensis Eiras & D’souza, 2004; M. indicum Tripathi, 1952; M. labeoi Boungou, Kabre Sakiti, Marques & Sawadogo, 2006; M. paratoyamai Kato, Kasai, Tomochi, Li & Sato, 2017; M. paratypicus Xi, Zhao, Li & Xie, 2019; M. nchoutnounensis Nchoutpouen & Fomena, 2011; M. koli Lalitha Kumari, 1969; M. mahendrae Sarkar, 1986; M. mrigalae Chakravarty, 1939; M. saranai (Tripathi, 1952); M. undasuturae Sarkar, 1994; M. analfinus Basu, Modak & Haldar, 2009). The species described here, M. wondjii sp. nov., appears to have a degenerate polar capsule with no visible polar tubule. This is most similar to M. bhadrensis, M. chilkensis, M. duodenalis, M. indicum, M. labeoi, M. paratoyamai, and M. paratypicus (Table 1). Several characteristics differentiate each of these from M. wondjii sp. nov. Myxobolus bhadrensis was found in the muscle of Labeo rohita Hamilton, 1822 in India. Its myxospores are smaller, with a thickening anterior end, measuring on average 9.5 × 7.1 µm, and a larger polar capsule averaging 3.5 × 2.2 µm. European Journal of Taxonomy 1022: 1–18 (2025) 8 Myxobolus chilkensis, a gall bladder parasite of L. rohita in India, has spherical to pyriform myxospores (7.2–8.0 × 5.6–6.6 μm). Their polar capsules are pyriform, with the larger being 3.2–4.8 × 1.8–2.2 μm in size, and the smaller having a narrow neck. Fig. 2. Photomicrographs of mature myxospores of Myxobolus wondjii sp. nov. A. Myxospores in frontal view. B. Myxospores in lateral (sutural) view. C. Myxospores stained with May-Grünwald-Giemsa. D. Diagrammatic drawing of a myxospore in valvular view. Scale bars = 5 µm. LEKEUFACK-FOLEFACK G.B. et al., Myxobolus wondjii sp. nov. from Labeo batesii 9 Table 1. Comparison of Myxobolus wondjii sp. nov. with morphologically similar species of Myxobolus. Myxospore dimensions are given in micrometers (µm). Arithmetic means are followed by ranges in parentheses. Abbreviations: ICA = intercapsular appendix; LPC = length of polar capsules; PC = relative length of polar capsules; PT = number of coils of polar tubule; SL = spore length; SW = spore width; WPC = width of polar capsules; * = relative to the large polar capsule; ** = relative to the small polar capsule; / = data not available. Parasite species Host species Infestation site Country SL SW PC LPC WPC PT ICA Reference Myxobolus wondjii sp. nov. Labeo batesii Gills Cameroon 12.4 ± 0.1 (12–13.2) 8.8 ± 0.07 (8.3–9.4) Unequal 5.4 ± 0.5 (4.8–6.3)* 1.6 ± 0.06 (1.4–1.7)** 3.2 ± 0.06 (2.7–3.7)* 1 ± 0.08 (0.9–1.1)** 9–11* / ** Absent Present study M. bhadrensis Labeo rohitaMuscle India 9.5 (8.0–11.0) 7.1 (7.0–8.0) Unequal 3.5 (3.0–4.0)* 2.5 (2.0–4.0)** 2.2 (2.0–3.0)* 1.7 (1.0–2.0)** / Absent Seenappa & Manohar (1981) M. chilkensis Labeo rohita Gill India 7.7 (7.2–8.0) 6.2 (5.6–6.6) Unequal 4.2 (3.2–4.8)* 1.0 (1.0–1.2)** 1.98 (1.8–2.2)* /** / Absent Kalavati et al. (1992) Kalavati & Nandi (2007) M. duodenalis Wallago attu Duodenum India 9.0 (8.5–9.5) 3.2 (2.7–3.7) Unequal 4.7 (4.0–5.4)* 2.7 (2.2–3.2)** 1.7 (1.36–2.16)* 1.0 (0.5–1.5)** 6–7* /** Absent Kaur & Singh (2011) M. indicum Cirrhina mrigala Muscles, liver, intestine India 9.5–10.8 7.5–8.2 2.7–3.6* 1.8** 1.8* 1.0** / Absent Tripathi (1952) M. labeoi Labeo coubie Between fin rays Burkina Faso 16.4 (16.0–17.0) 10.7 (10.0– 12.0) Unequal 8.3 (7.0–9.0)* 1.5 (1.6–2.0)** 6.5 (5–7)* 0.4 (0.3–0.5)** 10* /** Absent Boungou et al. (2006) M. paratoyamai Cyprinus carpio Gills Japan 15.4 (14.7–16.4) 6.3 (5.5– 6.8) Unequal 6.5 (5.9–7.1)* /** 3.7 (3.1–4.2)* /** 5–6* /** Absent Kato et al. 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The other members of the consortium are: Natural History Museum of Denmark, Copenhagen, Denmark; Naturalis Biodiversity Center, Leiden, the Netherlands; Museo Nacional de Ciencias Naturales-CSIC, Madrid, Spain; Leibniz Institute for the Analysis of Biodiversity Change, Bonn–Hamburg, Germany; National Museum of the Czech Republic, Prague, Czech Republic; The Steinhardt Museum of Natural History, Tel Aviv, Israël.