Nanotrema niokoloensis sp. nov. and a redescription of N. citharini Paperna, 1969 (Monogenea, Dactylogyridae) from the gills of Citharinus citharus citharus (Characiformes, Citharinidae) from Senegal

Abstract

One previously described and 1 new species of Nanotrema Paperna, 1969 are reported from the gills of Citharinus citharus citharus (Citharinidae) collected from the Niokolo Koba River, Senegal. Nanotrema citharini Paperna, 1969 is redescribed, based on the re-examination of the type specimens and new information obtained from material taken in Senegal (new locality record). Nanotrema niokoloensis sp. nov. is distinguished primarily by possessing a copulatory organ composed of a long thin tube with median portion usually coiled into about 2.5 rings and an accessory piece resembling a braid lying within the rings. Based on the presence of the dorsal anchors modified into paired haptoral spikes, which lack an associated bar, species of Nanotrema phenotypically appear to be related to those of Neotropical Rhinoxenus Kritsky, Boeger et Thatcher, 1988 and Indian Spicocleidus Agrawal, Tripathi et Shukla, 2005.

Description of Afrogyrodactylus ardae sp. n. (Monogenea: Gyrodactylidae) from Rhabdalestes septentrionalis (Characiformes: Alestidae) in the Niokolo-Koba National Park, Senegal

“…For example, the Distichontidae which includes 101 species in 17 genera, have no published record of infection by monogeneans. The Hepsedidae, with fi ve species in one genus, have been found to host only three monogenean species (Ndouba et al, 1997) and fi sh of Citharinidae, currently consisting of eight species in three genera, are known to be parasitized by three monogenean species (Musilová et al, 2011;Přikrylová et al, 2017). This clearly shows that the lack of the knowledge on parasite fauna on certain host groups can be very high.…”

Description of Citharodactylus gagei n. gen. et n. sp. (Monogenea: Gyrodactylidae) from the moon fish, Citharinus citharus (Geoffroy Saint-Hilaire), from Lake Turkana

“…The only monogenean genus that has been described from citharinids is Nanotrema, which includes three species parasitising C. citharus (see Paperna 1969;Khalil and Polling 1997;Musilová et al 2011). The current knowledge of parasites from characiform fish is still very limited, however, the description of another new viviparous gyrodactylid genus, such as Citharodactylus n. gen., suggests that parasite diversity on African fish is still highly unexplored.…”

“…Of these, the accounts focus on two species, i.e. Nanotrema citharini Paperna, 1969 described from Ghanaian populations and, Nanotrema niokoloensis Musilová, Řehulková et Gelnar, 2011(see Paperna 1969Khalil and Polling 1997;Musilová et al 2011) described from Senegal. In addition to these monogeneans, C. citharus is also a host to several myxozoans, i.e.…”