Dendromonocotyle colorni sp n. (Monogenea : Monocotylidae) from the skin of Himantura uarnak (Dasyatididae) from Israel and a new host record for D-octodiscus from the Bahamas

Dendromonocotyle colorni sp. n. (Monogenea: Monocotylidae) is described fro m the dorsal skin surface of two specimens of Himantura uarnak (Forsskal) k ept at the Eilat Underwater Observatory in Israel. Dendromonocotyle colorni is distinguished from the other eight species in the genus by the morpholo gy of the terminal papillar sclerite on the haptor, the distal portion of t he male copulatory organ and the morphology of the vagina. The development of the male copulatory organ is detailed for D. colorni and the adaptations of species of Dendromonocotyle to life on the dorsal skin surface of rays are discussed. Dendromonocotyle octodiscus Hargis, 1955 was identified from the dorsal skin surface of the southern stingray Dasyatis americana Hildeb rand et Schroeder off Bimini, Bahamas and represents a new host record.