Neoentobdella gen nov for species of Entobdella Blainville in Lamarck, 1818 (Monogenea, Capsalidae, Entobdellinae) from stingray hosts, with descriptions of two new species

The knowledge that entobdelline (capsalid) monogeneans formerly in Entobdella fall into two natural groupings provides the background to this paper. It is proposed to retain Entobdella for E. hippoglossi (type species), E.pugetensis and E. soleae from teleost flatfishes and to erect Neoentobdella gen. nov. for those parasites formerly in Entobdella but infecting elasmobranch flatfishes (mostly dasyatid stingrays but one report from a rhinobatid host). Neoentobdella diadema comb. nov. is designated type species for the new genus, which also includes N. apiocolpos comb. nov., N. australis comb. nov., N. bumpusii comb. nov. and two new species, N. natans sp. nov. and N. parvitesticulata sp. nov. from the dasyatid stingrays Pastinachus sephen and Himanturafai, respectively, caught off the Great Barrier Reef, Queensland, Australia. A prominent feature of all Neoentobdella species is the possession of anterior adhesive pads with transverse rays, resembling a diadem, but the close relationship between N. natans and N. parvitesticulata is underlined by the presence in both species of a muscular pad armed with microsclerites inside the genital atrium and elaborate fleshy lips and folds on the dorsal surface near the common genital opening. Adults of both species are also able to swim. The validity of Pseudoentobdella pacifica is confirmed. Entobdellinae Bychowsky, 1957 is revised to accommodate the recently established Listrocephalos, as well as the proposal of Neoentobdella.