REDESCRIPTION OF PARABENEDENIELLA POSTEROCOLPA (HARGIS, 1955) BRULE AND BULLARD N. GEN. ET N. COMB. (MONOGENOIDEA: CAPSALIDAE: ENTOBDELLINAE) FROM INFECTIONS ON THREE BATOID HOSTS (RHINOPTERIDAE AND MOBULIDAE) WITH PHYLOGENETIC ANALYSIS AND COMMENTS ABOUT CAPSALID HOST SPECIFICITY.

We herein propose Parabenedeniella Brule and Bullard n. gen. to accommodate Parabenedeniella posterocolpa n. comb., formerly of Benedeniella Johnston, 1929 (both Capsalidae: Entobdellinae). Parabenedeniella differs from all other entobdelline genera by the combination of having a U-shaped (not looped) proximal portion of the cirrus sac, a vagina that is directed posterolaterad, a tube-like proximal portion of the vagina that is approximately one-third of the total length of the vagina, a thick-walled and muscular distal portion of the vagina that is approximately two-thirds of the total length of the vagina, and a dorsal vaginal pore that is submarginal to the sinistral body margin posterior to or at the level of the testes. We collected specimens of P. posterocolpa from 5 cownose rays, Rhinoptera bonasus (Rhinopteridae), and 1 Brazilian cownose ray, Rhinoptera brasiliensis, from the Gulf of America and from 1 giant manta, Mobula birostris (Mobulidae), from an exhibit tank at a public aquarium, which also contained cownose rays. Parasite specimens were fixed in 10% neutral buffered formalin for morphology or preserved in 95% EtOH for DNA extraction. All of the collected specimens of P. posterocolpa were morphologically indistinguishable from the holotype of P. posterocolpa and were diagnosed by having anterior attachment organs, each with anteroventral grooves and a dorsal papilla, and a dorsal vaginal pore located level with or posterior to the testes. We generated 15 sequences: the ITS1, 28S, and COI from 2 specimens of P. posterocolpa from a cownose ray and 2 specimens from a giant manta plus a specimen from the Brazilian cownose ray. The only extant 28S sequence previously ascribed to P. posterocolpa was identical to each of our 28S sequences (no previous ITS1 or COI sequences for P. posterocolpa exist), and the new ITS1 sequences were identical. Two morphologically identical specimens of P. posterocolpa spaced approximately 5 mm apart on a single host specimen had distinct COI sequences (2 bp or 0.2% difference). The 28S analysis recovered P. posterocolpa as a sister to a clade comprising species of Entobdella and Neoentobdella (all Entobdellinae). The 28S and COI phylogenetic analyses recovered Entobdellinae as sister to Capsalinae; both were recovered as sister to Dionchinae (both Capsalidae). This is the first study of P. posterocolpa that combines morphology and nucleotide sequences from multiple infections and host species, the first record of P. posterocolpa infecting the Brazilian cownose ray, and the first detailed taxonomic description of specimens of P. posterocolpa infecting the giant manta.