Species of Alestidae are known to be parasitised by dactylogyrid monogeneans representing three genera, Afrocleidodiscus Paperna, 1969, Annulotrema Paperna & Thurston, 1969, and Characidotrema Paperna & Thurston, 1968. The objective of the present study was to investigate the species diversity of Monopisthocotylea of African tetras from the Lower Phongolo River and floodplain in South Africa. Four new and two previously described species of Annulotrema were identified from the gills of three species of African tetras, Brycinus imberi, Hydrocynus vittatus, and Micralestes acutidens. The collected parasites were studied using two complementary approaches: morphology of hard sclerotised structures, and molecular markers using rDNA sequence data (28S rDNA, 18S rDNA, and ITS1). Three new species, Annulotrema arcum n. sp., Annulotrema caputfemoris n. sp., and Annulotrema strepsiceros n. sp., were described from B. imberi and one species, Annulotrema retortum n. sp., from M. acuditens. Two previously described species, Annulotrema pikoides Guégan, Lambert and Birgi, 1988 and A. pseudonili Kičinjaová and Řehulková, 2017, were newly recorded from H. vittatus in South Africa. Annulotrema arcum n. sp. and A. caputfemoris n. sp. share similar male copulatory organ morphologies, suggesting a close phylogenetic relationship as sister taxa. Despite weak nodal support, A. strepsiceros n. sp. shows morphological congruence with the former two species, reinforcing their molecular linkage. The present study shows a critical need for the exploration of monopisthocotylean diversity and the paucity of available molecular data of representatives from this group.

TITLE: Espèces d'Annulotrema (Monopisthocotylea, Dactylogyridae) parasitant des tétras africains (Characiformes, Alestidae) dans la rivière Phongolo, en Afrique du Sud, avec description de quatre nouvelles espèces. ABSTRACT: Les espèces d'Alestidae sont connues pour être parasitées par des monogènes Dactylogyridae représentant trois genres, Afrocleidodiscus Paperna, 1969, Annulotrema Paperna & Thurston, 1969 et Characidotrema Paperna & Thurston, 1968. L'objectif de la présente étude était d'examiner la diversité des espèces de Monopisthocotylea des tétras africains du cours inférieur de la rivière Phongolo et de sa plaine inondable en Afrique du Sud. Quatre nouvelles espèces d'Annulotrema et deux espèces déjà décrites ont été identifiées à partir des branchies de trois espèces de tétras africains, Brycinus imberi, Hydrocynus vittatus et Micralestes acutidens. Les parasites collectés ont été étudiés en utilisant deux approches complémentaires, la morphologie des structures sclérifiées et les marqueurs moléculaires utilisant des données de séquence d'ADNr (ADNr 28S, ADNr 18S et ITS1). Trois nouvelles espèces, Annulotrema arcum n. sp., Annulotrema caputfemoris n. sp. et Annulotrema strepsiceros n. sp., ont été décrites chez B. imberi et une espèce, Annulotrema retortum n. sp., chez M. acuditens. Deux espèces précédemment décrites, Annulotrema pikoides Guégan, Lambert et Birgi, 1988 et A. pseudonili Kičinjaová et Řehulková, 2017, ont été nouvellement répertoriées chez H. vittatus en Afrique du Sud. Annulotrema arcum n. sp. et A. caputfemoris n. sp. partagent des morphologies similaires de l’organe copulateur mâle, suggérant une relation phylogénétique étroite de taxons frères. Malgré un faible support nodal, A. strepsiceros n. sp. présente une congruence morphologique avec les deux premières espèces, renforçant leur lien moléculaire. La présente étude montre qu'il est essentiel d'explorer la diversité des Monopisthocotylea et que les données moléculaires disponibles sur les représentants de ce groupe sont rares.

• Klíčová slova
• 28S rDNA, Alestidae, Annulotrema, Monogenea, South Africa,
• MeSH
• Characiformes * parazitologie   MeSH
• DNA helmintů MeSH
• fylogeneze * MeSH
• infekce červy třídy Trematoda * veterinární   parazitologie   MeSH
• mezerníky ribozomální DNA genetika   MeSH
• nemoci ryb * parazitologie   MeSH
• ploštěnci klasifikace   anatomie a histologie   genetika   izolace a purifikace   MeSH
• řeky * MeSH
• ribozomální DNA MeSH
• RNA ribozomální 18S genetika   MeSH
• RNA ribozomální 28S genetika   MeSH
• Trematoda * klasifikace   anatomie a histologie   genetika   izolace a purifikace   MeSH
• žábry * parazitologie   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Jihoafrická republika MeSH
• Názvy látek
• DNA helmintů MeSH
• mezerníky ribozomální DNA MeSH
• ribozomální DNA MeSH
• RNA ribozomální 18S MeSH
• RNA ribozomální 28S MeSH

BACKGROUND: African tetras (Alestidae) belonging to Brycinus Valenciennes are known to be parasitized with monogeneans attributed to two genera, Annulotrema Paperna & Thurston, 1969 and Characidotrema Paperna & Thurston, 1968 (Dactylogyridae). During a survey of monogeneans parasitizing alestids, species of Characidotrema were collected in Cameroon, D. R. Congo, Senegal, South Africa, Sudan and Zimbabwe. This paper provides new morphological data and the first molecular analysis broadening our knowledge on the diversity of these parasites. RESULTS: Seven species (four known and three new) of Characidotrema are reported from two species of Brycinus: C. auritum n. sp. and C. vespertilio n. sp. from B. imberi (Peters); and C. brevipenis Paperna, 1969, C. nursei Ergens, 1973, C. pollex n. sp., C. spinivaginus (Paperna, 1973) and C. zelotes Kritsky, Kulo & Boeger, 1987 from B. nurse (Rüppell). Species identification was based on morphological analysis of the sclerotized structures supported by nuclear ribosomal DNA (partial 18S rDNA, ITS1, and 28S rDNA) sequence data. Morphological analysis confirmed that the most apparent character distinguishing species in the genus is the morphology of the male copulatory organ and vagina. Observations on the haptoral sclerotized elements of these parasites by means of phase contrast microscopy revealed the presence of a sheath-like structure relating to the ventral anchor, a feature that supplements the generic diagnosis of Characidotrema. Maximum Likelihood and Bayesian analyses of the large subunit (28S) rDNA sequences recovered Characidotrema species isolated from the two Brycinus hosts as monophyletic, and indicated a closer relationship of this group to monogeneans parasitizing African cyprinids (Dactylogyrus spp.) and cichlids (species of Cichlidogyrus Paperna, 1960, Scutogyrus Pariselle & Euzet, 1995, and Onchobdella Paperna, 1968) than to those from catfishes (species of Quadriacanthus Paperna, 1961, Schilbetrema Paperna & Thurston, 1968 and Synodontella Dossou & Euzet, 1993). The overall agreement between the morphological diversification of the MCOs and the molecular tree observed in this study indicates that significant phylogenetic signals for clarifying relationships among species of Characidotrema are present in the characteristics of the MCO. CONCLUSIONS: It seems that intra-host speciation is an important force shaping the present distribution and diversity of Characidotrema but further studies are necessary to confirm this hypothesis and assess questions related to the phylogeny of these parasites. To identify potential co-speciation events, co-phylogenetic analyses of these monogeneans and their alestid hosts are required.

• Klíčová slova
• Africa, Alestidae, Brycinus, Characidotrema, DNA, Dactylogyridae, Diversity, Monogenea,
• MeSH
• cichlidy parazitologie   MeSH
• fylogeneze * MeSH
• interakce hostitele a parazita * MeSH
• jezera parazitologie   MeSH
• nemoci ryb parazitologie   MeSH
• ribozomální DNA genetika   MeSH
• Trematoda klasifikace   izolace a purifikace   MeSH
• žábry parazitologie   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• subsaharská Afrika MeSH
• Názvy látek
• ribozomální DNA MeSH

BACKGROUND: African catfishes of the families Bagridae and Clariidae are known to be parasitized with monogeneans of Quadriacanthus Paperna, 1961 (Dactylogyridae). The genus remains taxonomically challenging due to its speciose nature and relatively wide host range representing two fish orders, i.e. Siluriformes and Osteoglossiformes, in Africa and Asia. Here, we investigated diversity of Quadriacanthus spp. parasitizing Clarias gariepinus (Burchell), Heterobranchus bidorsalis Geoffroy Saint-Hilaire, and Bagrus docmak (Forsskål) collected in the Lake Turkana (Kenya) and Nile River Basin (Sudan). The interspecific relationships among Quadriacanthus spp. parasitizing catfishes inferred from ribosomal DNA sequences were investigated for the first time. METHODS: A combined morphological and molecular approach was used for description of the new species and for a critical review of the previously described Quadriacanthus spp., by means of phase contrast microscopic examination of sclerotized structures, and assessing the genetic divergence among the species found using rDNA sequences. RESULTS: Seven species (including four new) of Quadriacanthus were identified. These were as follows: Quadriacanthus aegypticus El-Naggar & Serag, 1986, Quadriacanthus clariadis Paperna, 1961, Quadriacanthus fornicatus n. sp., Quadriacanthus pravus n. sp., and Quadriacanthus zuheiri n. sp. from Clarias gariepinus (Clariidae); Quadriacanthus mandibulatus n. sp. from Heterobranchus bidorsalis (Clariidae); and Quadriacanthus bagrae Paperna, 1979 from Bagrus docmak (Bagridae). For both 18S-ITS1 and 28S rDNA regions, Q. clariadis from a clariid fish was found to be most closely related to Q. bagrae from a bagrid host. Quadriacanthus mandibulatus n. sp. was observed to be the most distant species from the others. The separation of Q. mandibulatus n. sp. from the other species corresponds with the different morphology of its copulatory tube. The copulatory tube is terminally enlarged in Q. mandibulatus n. sp., while the tube in all other congeners studied is comparatively small and with an oblique tapering termination. CONCLUSIONS: This study contributes to a better understanding of African dactylogyrid diversity and provides the first molecular characterization of Quadriacanthus spp. The observed interspecific genetic relationships among Quadriacanthus spp. from clariids and Q. bagrae from a bagrid host suggest a possible host-switching event in the evolutionary history of the genus. Our records extend the currently known geographical range for Quadriacanthus spp. to Kenya and Sudan.

• Klíčová slova
• Africa, Catfishes, DNA, Dactylogyridae, Lake Turkana, Monogenea, New species, Nile River Basin, Quadriacanthus, Siluriformes,
• MeSH
• fylogeneze MeSH
• infekce červy třídy Trematoda epidemiologie   parazitologie   veterinární   MeSH
• jezera parazitologie   MeSH
• nemoci ryb epidemiologie   parazitologie   MeSH
• ploštěnci klasifikace   genetika   izolace a purifikace   MeSH
• řeky parazitologie   MeSH
• ribozomální DNA MeSH
• sumci parazitologie   MeSH
• Trematoda genetika   MeSH
• žábry parazitologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Asie epidemiologie   MeSH
• Keňa epidemiologie   MeSH
• Súdán epidemiologie   MeSH
• východní Afrika epidemiologie   MeSH
• Názvy látek
• ribozomální DNA MeSH