Ergasilus cerastes sp. n. (Copepoda: Cyclopoida) from North American Catfishes

Abstract

Ergasilus cerastes sp. n. is described from specimens collected in a fish market in Washington, D. C. The specimens are conspecific with those reported by Mueller (1936) as Ergasilus elegans from Florida Ictalurus spp. Wilson (1911) described Ergasilus versicolor from Ictalurus natalis, and he apparently based his description on specimens belonging to two separate species (Roberts, 1969). Later, he described E. elegans Wilson, 1916, which was reduced to synonymy with E. versicolor by Roberts (1969) since his description and the available type material of E. elegans are in close agreement with the types of E. versicolor. E. versicolor was redescribed based on the type specimens, and the other specimens included in Wilson's (1911) report were described as new (E. arthrosis Roberts, 1969). Mueller (1936) reported E. elegans from Ictalurus spp. in Florida, and he noted that his specimens differed from the original description in some respects. Specimens which are undoubtedly the same species as that reported by Mueller as E. elegans have become available to the present author. They were collected from catfish in a fish market in Washington, D. C. by Dr. T. E. Bowman, 28 June 1966. Although these appear to be closely related to E. versicolor (= E. elegans), they are sufficiently different to be regarded as a separate species. Methods and terminology are mostly as used previously (Roberts, 1969). Specimens were cleared and mounted unstained in glycerine jelly, polyvinyl lactophenol (G. Gurr), or lactic acid, and slides were made permanent by ringing with ordinary cosmetic fingernail enamel. Received for publication 17 June 1969. * This investigation was supported in part by grant AI-06153, from the NIH, U. S. Public Health Service. Ergasilus cerastes sp. n. Synonymy: Ergasilus elegans Wilson, 1916, of Mueller, 1936.