Mehracotyle insolita n. gen., n. sp., a gill parasite of Rhinobatos cemiculus Geoffroy Saint-Hilaire, 1817 in Tunisia, is distinguished from all other Monocotylidae by its ovary which does not surround the right intestinal branch, and is also characterized by a seminal receptacle in two parts and an apparently absent vagina. The morphology of the new genus Mehracotyle n. gen. distinguishes it, among the Monopisthocotylea, from the Loimoidae, and among the Monocotylidae, from the genera Anoplocotyloides Young, 1967, Troglocephalus Young, 1967 and Neoheterocotyle Hargis, 1955, also parasites of Rhinobatidae. Mehracotyle n. gen. is for the time being classified among the Dasybatotreminae. Description of the new genus leads to modify the diagnosis of the Dasybatotreminae and Monocotylidae in introducing the character "ovary surrounding or not the right intestinal branch".
Plathelminthes, Monogenea, Monocotylidae, Mehracotyle n. gen., Euselachii, Rhinobatos cemiculus, parasite, gills, Tunisia, new genus, new species.