Search

Purpose: To study the monogeneans gill parasites of Heterobranchus bidorsalis (Siluriformes, Clariidae) fish of economic interest in the Bagoue River. Methods: Fifty-five specimens of H. bidorsalis were caught with gillnets in the Bagoué River from August 2018 to January 2019. The monogeneans were individually isolated from the gill and transferred directly onto a slide in a drop of glycerin ammonium picrate mixture (GAP). Results: The new species differ from the previously described Quadriacanthus spp. mainly by the morphology of their sclerotised vagina: Quadriacanthus tanoyaoi sp. nov having a V-shaped, widely open vagina with a central protuberance, and Quadriacanthus bidorsalisi sp. nov having a pear-shaped vagina, composed of a tubular part with a ring near the aperture and a swollen portion. Q. tanoyaoi sp. nov and Q. bidorsalisi sp. nov are different in the shape of the dorsal and ventral anchors (more sturdy for Q. tanoyaoi), of the dorsal and ventral cuneus (triangular vs Y-shaped, respectively), and that of the vagina (V-shaped, widely open with a central protuberance vs pear-shaped, respectively). Conclusion: To date, only Quadriacanthus mandibulatus Francová & Řehulková, 2017 were recognised parasitizing from H. bidorsalis from the Nile River Basin (Sudan) and Lake Turkana (Kenya). The present study with the description of 2 new species expands the number to 3 species of monogeneans for this fish. [ABSTRACT FROM AUTHOR]

Four species of Synodontella, including three new, are reported from three species of Synodontis (S. ocellifer, S. nigrita, and S. velifer) from north-western Côte d'Ivoire. Synodontella melanoptera Dossou & Euzet, 1993 was found on the gills of S. nigrita and S. velifer and was already known from the gills of S. melanopterus in Benin and the gills of S. obesus and S. rebeli in Cameroon. The new species are Synodontella speroadotevii n. sp. from S. nigrita (type-host), S. velifer and S. ocellifer, and Synodontella bagoueensis n. sp. and Synodontella akengboi n. sp., both from S. velifer (type-host for both), S. nigrita and S. ocellifer. The new species differ from the other species of Synodontella mainly in the morphology of their male copulatory organs (MCO): Synodontella speroadotevii has a two-part penis (one being a hollow tube and the other a flattened tube); Synodontella bagoueensis has a wide G-shaped penis with a sub-terminal opening; and Synodontella akengboi has a simple narrow J-shaped penis. Synodontella speroadotevii differs from Synodontella bagoueensis and Synodontella akengboi in the shape of the dorsal transverse bar, which shows no protuberance, and also in the morphology of the MCO. Synodontella bagoueensis differs from the other two species in that it has a dorsal transverse bar that is V-shaped and a G-shaped MCO. Synodontella akengboi differs from the two other species in having a J-shaped MCO and in the size of its ventral and dorsal anchors which, contrary to the other two species, are almost similar., (© E. Bouah et al., published by EDP Sciences, 2019.)