Lepeophtheirus semicossyphi Yamaguti, 1939

Venmathi Maran, B. A., Ohtsuka, Susumu & Shang, Xu, 2012, Records of Adult Caligiform Copepods (Crustacea: Copepoda: Siphonostomatoida) in Marine Plankton from East Asia, Including Descriptions of Two New Species of Caligus (Caligidae), Species Diversity 17 (2), pp. 201-219 : 212

Lepeophtheirus semicossyphi Yamaguti, 1939 ( Fig. 9A )

Lepeophtheirus semicossyphi Yamaguti, 1939: 443 ; Shiino 1963: 409; Yamaguti 1963: 409; Kim 1998: 717.

Material examined. One adult ♀ (KMNH IvR 500,507), off Iheya Island , Okinawa Prefecture, Japan (St. 8), 22 May 2008 ( Table 1) .

Description. Female. Body ( Fig. 9A ) 5.06 mm long excluding caudal setae. Cephalothorax suborbicular 3.03× 2.89 mm, slightly longer than wide. Fourth pediger 0.51× 0.85 mm, wider than long. Genital complex globose, 1.42× 1.70 mm, wider than long, with convex lateral margins and 2 prominent posterolateral projections. Abdomen small, 0.20× 0.32 mm, wider than long. Caudal ramus 0.09× 0.12 mm, wider than long, with 3 long and 3 short plumose setae.

Remarks. This is the first record of adult Lepeophtheirus in a plankton sample. Lepeophtheirus semicossyphi is parasitic on the wrasse Semicossyphus reticulatus (Valenciennes, 1839) and was originally reported from Tarumi, Hyogo Prefecture, Japan ( Yamaguti 1939). It was subsequently report- ed from the same host elsewhere in Japan ( Shiino 1963) and in Korea ( Kim 1998).

Figures

Fig. 9. Two other caligid genera from plankton samples. A, Lepeophtheirus semicossyphi Yamaguti, 1939, female (KMNH IvR 500,507), habitus, dorsal view; B, Metacaligus uruguayensis Thomsen, 1949, female (KMNH IvR 500,508), habitus, dorsal view.Scale bars: 1mm (A–B).