A new species of Neoheterocotyle Hargis, 1955 (Monogenea: Monocotylidae) from the gills of Rhinobatos annulatus Müller & Henle (Rhinobatidae) off the southern tip of Africa

Neoheterocotyle robii n. sp. is described from the gills of four female Rhinobatos annulatus Müller & Henle caught as bycatch during routine demersal research trawls off the Southern Cape coast of South Africa. The new species can be distinguished from all other members of Neoheterocotyle Hargis, 1955 by the morphology of the accessory piece associated with the male copulatory organ, the presence of a distinct horseshoe-shaped muscle associated with the male copulatory organ and the presence of a sclerotised structure in the proximal portion of the vagina. This is the first Neoheterocotyle species described from South African waters.