ON THE DEVELOPMENT OF PARASITIC COPEPODA II. COLOBOMATUS PUPA IZAWA (CYCLOPOIDA : PHILICHTHYIDAE)

Abstract

Following the previous and first paper of the present serial studies, dealing with the free-living stages of Sarcotaces, this paper describes the free stages of a species of Colobomatus which belongs, together with Sarcotaces, to the family Philichthyidae of the Copepoda. Colobomatus Hesse, 1873, is an endoparasitic genus, found in the cephalic sensory canal system of fishes. Because of such a secret habitat, in addition to smallness of the animal body, it is difficult to detect specimens of this genus only by surface examination of host fishes, and thus little has been known in general about the genus. Though twenty-four species have been described so far, no larvae have ever been found or described. In 1971 three species of this genus were found and described as new species for the first time from the Japanese waters (Izawa, 1974). One of which, C. pupa lzawa obtained from the Japanese goat fish, Pseudupeneus spilurus (Bleeker), was examined throughout its whole free-living developmental stages traced by rearing larvae.