NEW GENUS AND SPECIES OF LIOLOPIDAE ODHNER, 1912 (PLATYHELMINTHES: DIGENEA) INFECTING NILE CROCODILE, CROCODYLUS NILOTICUS (LAURENTI, 1768) (CROCODILIA: CROCODYLIDAE) IN THE KAVANGO RIVER, NAMIBIA.

Abstract

The intestine of a large adult (male) Nile crocodile, Crocodylus niloticus (Laurenti, 1768) (Crocodilia: Crocodylidae) from a site (18°08'24.5''S, 21°40'58.4''E) on the Kavango River (Namibia) was infected by Ngubuvangandu francoisjacobsi Dutton and Bullard n. gen., n. sp. (Digenea: Liolopidae). The new genus and species differs from all other liolopids by the combination of having a linguiform body that is ∼3 times longer than wide, a weakly muscular ventral sucker (with pre- and post-ventral sucker distances equal), lobed testes that nearly span the intercecal space and that occupy the posterior one-third of the body, a posterior testis that occupies the space between the tips of the posterior ceca, an ovary abutting the anterior testis, a vitellarium that extends anterior to the ventral sucker (not reaching cecal bifurcation), and a uterus that traverses the intercecal space immediately anterior to the anterior testis. We herein reassign two previously named crocodilian liolopids formerly of Dracovermis Brooks and Overstreet, 1978 to the new genus: Ngubuvangandu brayii (Baylis, 1940) Dutton and Bullard, 2024 (infecting the west African slender snouted crocodile, Mecistops cataphractus Cuvier, 1825 in the Congo River) and Ngubuvangandu rudolphii (Tubangui and Masilungan, 1936) Dutton and Bullard, 2024 (infecting the saltwater crocodile, Crocodylus porosus Schneider, 1801 in the Philippines). The phylogenetic analysis recovered the new genus sister to Liolope Cohn, 1902. That clade was sister to Harmotrema Nicoll, 1914, with Dracovermis sister to the clade and Paraharmotrema Dutton and Bullard, 2022, sister to all liolopids analyzed. This result demonstrates that the crocodilian liolopids are paraphyletic, rejecting the notion that natural groups of liolopids can be defined by the definitive host they infect (i.e., no evidence of phylogenetic host specificity of liolopid genera/lineages). This is the first liolopid described from the Nile crocodile and only the second liolopid species described from an African crocodilian.