TWO NEW SPECIES OF COPEPODS PARASITIC ON JAPANESE FISHES

Abstract

With Plate IX Of the two species described here, one was found at the Tamano Marine Laboratory of Okayama University, and the other at the Fish Culture Ground of Kinki University at Sirahama, Wakayama Prefecture. Thanks are due to the authorities of the two institutions for their generous supply of the material. Family CHONDRACANTHIDAE 1. Pseudacanthopsis secunda n. sp. (Pl. IX, Figs. 1-6) Habitat : Gills of Apogon lineatus TEMM. et ScHLEG. Material: 5 gravid females. Locality and date : Inland Sea, August, 1959. Body 1.3-1.5 mm in length, including first antenna and posterior lobe of trunk. Cephalothorax semicircular 0.5-0.55 x 0.65-0.73 mm, with its anterolateral corner produced prominently in form of a rounded prominence and its convex frontal margin bordered by T-shaped, heavily sclerotized rib. Neck short. Trunk 0.85-1.0 x 0.9-1.2 mm, strongly convex dorsally and broadly rounded anteriorly and laterally, with paired, rounded, conical, posterior lobes projecting backward beyond abdomen. Genital segment small, inverted trapezoidal, about 60,u long, 0.14 mm broad at base. Abdomen wider than long, about 0.05 x 0.1 mm, with broadly rounded 1)