ON THREE NEW SPECIES OF COLOBOMATUS (CYCLOPOIDA : PHILICHTHYIDAE) PARASITIC ON JAPANESE FISHES

Abstract

Colobomatus is a copepod genus found parasitic in the cephalic sensory canal system of fish. Showing a pronounced sexual dimorphism, it has an almost immobile female, which keeps itself with curious assortment of processes in the narrow passage, and a mobile, much smaller male retaining much of ordinary copepod features. Twenty-four species of this genus thus far known are the parasites of marine teleosts except C. lamnae which has been recorded from an elasmobranch. In this note, three additional species recently found in Japan are described, respectively under the names, C. pupa n. sp., C. exilis n. sp., and C. fusiformis n. sp. The record represents the first discovery of the genus from Japanese waters and the second one from the Pacific, in which C. embiotocae has been obtained from several Californian species of embiotocids (Noble et al., 1969; Iverson, 1972).