A new genus and species of monogenean belonging to the Gyrodactylidae, Citharodactylus gagei n. gen. et n. sp. (Plathyhelminthes, Monogenea), is described from the gills of the moon fish, Citharinus citharus (Geoffroy Saint-Hilaire), a characiform fish collected from Lake Turkana in northern Kenya. The new viviparous genus can be readily distinguished from the six other gyrodactylid genera recorded from Africa and from the other viviparous genera within the Gyrodactylidae based on the morphology of the male copulatory organ (MCO), which consists of a muscular ovate organ with an opening onto the tegument through which the narrow tapered end of a sclerotised curved cone-shaped structure protrudes. The tegumental opening of the MCO is surrounded by a collar of short spines. Sequencing of the nuclear ribosomal DNA internal transcribed spacers 1 and 2, the 5.8S and the 18S rDNA genes and a comparison with the gyrodactylid species listed in GenBank confirmed the specimens are unique and do not match with any existing entry. When phylogenies for each genomic region were conducted (i.e. 0.064 gamma-corrected pairwise genetic distance based on a alignment of 1750 bp of the 1857 bp long 18S rDNA gene), the most similar match was that of Afrogyrodactylus sp. [= A. girgifae (Folia Parasitol 61:529-536, 2014)] from Brycinus nurse (Rüppell). The proposed name of the new parasite is Citharodactylus n. gen. which represents the seventh gyrodactylid genus to be found in Africa and the 25th viviparous genus and the 32nd genus to be added to the Gyrodactylidae.

Department of Botany and Zoology Faculty of Science Masaryk University Kotlařská 2 611 37 Brno Czech Republic Water Research Group Unit for Environmental Sciences and Management North West University Private Bag X6001 Za 2520 Potchefstroom South Africa Department of Biodiversity School of Molecular and Life Sciences University of Limpopo Private Bag X1106 ZA 0727 Sovenga South Africa

Fish Vet Group Asia Limited 99 386 Chaengwattana Building Chaengwattana Rd Kwaeng Toongsonghong Khet Laksi Bangkok 10210 Thailand Institute of Aquaculture Faculty of Natural Sciences University of Stirling Stirling FK9 4LA UK

Institute of Aquaculture Faculty of Natural Sciences University of Stirling Stirling FK9 4LA UK

References provided by Crossref.org