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Syst Parasitol (2010) 77:215231 DOI 10.1007/s11230-010-9269-4
Pseudohatschekiidae, a new family for Pseudohatschekia branchiostegi Yamaguti, 1939 (Crustacea: Copepoda: Siphonostomatoida) from Branchiostegus spp. (Teleostei: Perciformes: Malacanthidae) in Japanese waters,with descriptions of the early developmental stagesof P. branchiostegi
Danny Tang Kunihiko Izawa Daisuke Uyeno
Kazuya Nagasawa
Received: 6 April 2010 / Accepted: 29 June 2010 Springer Science+Business Media B.V. 2010
Abstract The siphonostomatoid copepod Pseudo-hatschekia branchiostegi Yamaguti, 1939 is redescribed in detail based on specimens of both sexes collected from the gill laments of three species of Branchiostegus Ranesque (Teleostei: Malacanthidae) captured in Japanese waters. Descriptions of two naupliar stages and the infective copepodid stage of P. branchiostegi are also provided for the rst time, and P. mebaru Yamaguti, 1939 is recognised herein as a junior synonym of P. branchiostegi. The latter copepod species represents a new family, the Pseudohatschekiidae fam. nov., of the Siphonostomatoida characterised by the following apomorphies: (a) two free pedigerous somites present between the cephalothorax and the genital complex; (b) a chelate antenna bearing two digitate processes and a thin cuticular covering; (c) a unilobate maxillule, with the palp completely fused to the endite and represented by a surface seta; (d) a rounded process furnished with pectinate membranes on the apex of the
maxillary basis; (e) 2-segmented rami on legs 13; and (f) the absence of leg 4. It is also now evident that P. branchiostegi is a relatively common and abundant parasite of Branchiostegus spp. in the Far East.
Introduction
The copepod genus Pseudohatschekia Yamaguti, 1939 was established by Yamaguti (1939a) in the siphonostomatoid family Dichelesthiidae Milne Edwards, 1840 to accommodate two new species, P. branchiostegi Yamaguti, 1939 obtained from the gills of the red tilesh Branchiostegus japonicus (Houttuyn) caught in the western North Pacic Ocean, off Kochi, Japan, and P. mebaru Yamaguti, 1939 collected from the gills of the darkbanded rocksh Sebastodes inermis (Cuvier) (= a junior synonym of Sebastes inermis Cuvier: see Kai & Nakabo, 2008) caught in the Seto Inland Sea, off Tarumi, Japan. Among the other four genera recognised in the Dichelesthiidae at that time, i.e. Dichelesthium Hermann, 1804, Lamproglena von Nordmann, 1832, Hatschekia Poche, 1902 and Pseudocongericola Y, 1933, Yamaguti (1939a) explicitly stated that Pseudohatschekia differs from Hatschekia in having a cheliform antenna, two pairs of maxillipeds (=...