A New Species of Urocleidus (Trematoda: Monogenea) from Gills of the White Perch, Morone americana (Gmelin)

Abstract

Urocleidus nactus sp. n. is described from the gills of the white perch, Morone americana (Gmelin), from North Carolina. Urocleidus nactus is the seventh species of Urocleidus to be described with a spurlike structure at the base of the anchor point and can be distinguished from other closely related species by the morphology of the hooks and of the accessory piece which is a 2-pronged fork. Urocleidus rogersi Hanek and Fernando 1972 is reported from the white perch, Morone americana, in North Carolina, and the white bass, Morone chrysops (Rafinesque), in North Carolina and Nebraska. Morphological variation of the accessory piece is described and a new interpretation of the haptoral armament is presented. Hosts were collected as part of a general study of the parasites of some fishes of North Carolina and Nebraska. Fish were collected and preserved in 10% formalin or brought to the laboratory alive. In the laboratory the gills were removed, placed in 70% alcohol, and shaken vigorously, or the gills of the living fish were removed and treated as prescribed by Rogers (1966). The monogeneans were recovered from the gill washings, mounted unstained in glycerin gel, or stained in Gomori's trichrome and mounted in a commercial resin. Measurements were made with an ocular micrometer and expressed in microns. Average measurements are followed by the ranges in parentheses. Illustrations were prepared with the use of a camera lucida. Urocleidus nactus sp. n. (Figs. 1-8) Host and locality: Morone americana (Gmelin), Albemarle Sound, North Carolina. Location on host: Gills. Specimens studied: 15. Type specimens: Holotype, USNM Helm. Coll. No. 73744; paratypes USNM Helm. Coll. No. 73745; Univ. Neb. State Mus., Manter Lab. No. 20233; remainder in the authors' collection.