Descriptions of the postembryonic developmental stages of Hatschekia bifurcata Yamaguti & Yamasu, 1959 (Copepoda, Siphonostomatoida, Hatschekiidae)

Abstract

A series of descriptions of postembryonic developmental stages of Hatschekia bifurcata Yamaguti & Yamasu, 1959 is presented based on free-living larvae reared from eggs detached from ovigerous females recovered from the branchial lamellae of Aulacocephalus temmincki Bleeker, 1855, as well as on copepodids I-VI from A. temmincki and Diploprion bifasciatum Cuvier, 1828 (Pisces, Perciformes, Serranidae). The number of naupliar stages preceding the infective copepodid I is three in this species as in H. multibarbatae Izawa, 2015. A diagnostic feature of the species, a hook-like ventral process on the fourth antennular segment of the female, is regarded as an enlarged seta and was found to appear after copepodid V. A correction in the previously given setation of leg 2 and a complemental description of the antennule of the adult female are made. The male of this species is herein described for the first time. The sexes become distinct at copepodid III, and then growth curves of both sexes diverge stage by stage, as in H. multibarbatae. Aulacocephalus temmincki is reported as a new host species for H. bifurcata.