In the framework of the study of Siluriform fish monogeneans of Lake Tanganyika, we described two new species of Bagrobdella from Auchenoglanis occidentalis, Bagrobdella vanhovei sp. nov. is characterized by the morphology of its MCO which is unique (terminal opening) and Bagrobdella vansteenbergei sp. nov. characterized by the size of its hooks, which are almost all of the same size, and its male copulating organ with a unique shape: sub-terminal opening and no membrane surrounding.

ABSTRACT In the framework of the study of Siluriform fish monogeneans of Lake Tanganyika, we described two new species of Bagrobdella Paperna, 1969 from Auchenoglanis occidentalis (Valenciennes, 1840). Bagrobdella vanhovei sp. nov. is characterized by the morphology of its MCO which is unique among its congeners, presenting a non-terminal opening, whereas the other species have a terminal opening, and Bagrobdella vansteenbergei sp. nov. characterized by the size of its hooks, which are almost all of the same size, and its male copulating organ with a unique shape: a sub-terminal opening and no membrane surrounding. The Multivariate analysis done on morphometrical characters shows that the new and already described species are well individualized, except for Bagrobdella parauchenoglanii Akoumba, Pariselle, Tombi & Bilong Bilong, 2017 and Bagrobdella fraudulenta Euzet & Le Brun, 1990 (but these two species are easily distinguishable by their morphology), and that B. vanhovei sp. nov. has a great intra-specific morphometrical variation.

ABSTRACT Clariidae is a group that includes many species that have great economic importance in both fisheries and fish culture. Monogenean parasites of fishes assigned to this family have been studied in Cameroon, but there have been no studies on Clarias submarginatus Peter, 1882, a fish that is traditionally consumed by the local people. The examination of 43 specimens identified as C. submarginatus from Lake Ossa (first record of this fish species in the Sanaga basin), revealed that some of them belong to Quadriacanthus and are new. Their identification was made based on the morphology and the size of sclerotized parts of the haptor and the male and female copulatory complexes. Quadriacanthus macruncus Bahanak, Nack & Pariselle sp. nov. and Quadriacanthus submarginati Bahanak, Nack & Pariselle sp. nov. are characterized by the morphology of their accessory piece, pointed, slightly curved and wider at medium level, equipped with two subterminal, symmetrical and similar spines for Q. macruncus sp. nov. and made up of one long tip flanked by a short spine and a bulb for Q . submarginati sp. nov., while Quadriacanthus ossaensis Bahanak, Nack & Pariselle sp. nov. is distinguished by the unique morphology of the penis, ending in a fork. The new species of Quadriacanthus are herein described and their host specificity is discussed.

ABSTRACT A new genus and species of Monogenoidea, Susanlimae ianwhittingtoni gen. nov., sp. nov., are proposed for dactylogyrids collected from the "Nuayang tipis", Pseudeutropius moolenburghae Weber & de Beaufort, 1913, which inhabits freshwater in Sumatra. While clearly a member of a putative clade that includes Asian and African catfish parasites, S. ianwhittingtoni sp. nov. differs from most members of this clade by having a bifurcated haptor that embraces the gill rakers of its host. This haptoral morphology and mode of attachment also occur in species of Bifurcohaptor Jain, 1958. However, species of Susanlimae gen. nov. are easily distinguished by the comparative morphology of their haptoral armature. In Susanlimae gen. nov., the ventral and dorsal bars are single, elongated, and inverted u-shaped (ventral bar short and two short dorsal bars in Bifurcohaptor spp.); the dorsal anchor is robust with well-defined roots (reduced roots and elongate shaft in Bifurcohaptor spp.); and the ventral anchor has an elongated, deep root (inconspicuous in Bifurcohaptor spp.).

Examination of gill parasites from Ophthalmotilapia ventralis (Boulenger, 1898) in Lake Tanganyika (Africa) revealed the presence of four new species of Monogenea, all members of Cichlidogyrus Paperna, 1960 (Ancyrocephalidae). In view of the systematic importance of haptoral structure, the fish host shows a remarkable diversity of morphological groups. Cichlidogyrus vandekerkhovei sp. nov. and C. makasai sp. nov. are especially characterized by the unusual length of the dorsal transverse bar auricles, while C. sturmbaueri sp. nov. is distinguished by the unique shape of the accessory piece of its male copulatory organ. Importantly, C. centesimus sp. nov. displays a number of features new to the genus, namely a spirally coiled thickening at the end of the penis, the absence of an accessory piece in the genital apparatus, and a hitherto unknown uncinuli configuration in the haptor. This is the first record of ancyrocephalid parasites from the Tanganyika basin. Some mechanisms possibly contributing to this yet unknown diversity are discussed, identifying topics deserving further scientific scrutiny.

The present work analyse monogenoids parasite diversity as one independent character, hoping they can characterize the white piranha (Serrasalmus rhombeus) populations by its high specificity. Study was carried out in four sub-basins (Iténez, Beni, Madre de Dios e Ichilo) from the Bolivian Amazon Basin. A total of 1135 parasites were obtained, belonging to six genera and 11 species: Anacanthorus jegui, A. amazonicus, A. rondonensis, A. gravihamulatus, A. sciponophallus, Anacanthorus sp.1, Anacanthorus sp.2, Anacanthorus sp.3; Notothecium deleastum, N. deleastoideum, Notozothecium teinodendrum; Mymarothecium galeolum; Anphithecium diclonophallum y Enallothecium aegidatum. The high parasite diversity could be related to one complex of populations or species of Serrasalmus rhombeus existent or extintic.

El presente trabajo analiza la diversidad de parásitos monogenoideos como un carácter independiente, esperando que por su alta especificidad, éstos parásitos puedan caracterizar las poblaciones de sus hospederos, la piraña blanca, Serrasalmus rhombeus. El estudio se llevó acabo en cuatro sub-cuencas de la Cuenca Amazónica Boliviana (Iténez, Beni, Madre de Dios e Ichilo); se obtuvieron 1135 parásitos, los cuales fueron agrupados en seis géneros y once especies: Anacanthorus jegui, A. amazonicus, A. rondonensis, A. gravihamulatus, A. sciponophallus, Anacanthorus sp.1, Anacanthorus sp.2, Anacanthorus sp.3; Notothecium deleastum, N. deleastoideum, Notozothecium teinodendrum; Mymarothecium galeolum; Anphithecium diclonophallum y Enallothecium aegidatum. La elevada diversidad de parásitos encontrada puede deberse a que existe o existió un complejo de especies o poblaciones diferenciadas de Serrasalmus rhombeus