биота российских вод японского моря - Materials of Alexey Shipunov

Abdomen cylindrical, pointed horizontally. Ocular tubercle low, situated on anteriormargin of cephalic segment. Oviger present not in all species. Legs short, robust, withsparse setae; tarsus very short; propodus curved, without basal spines. Main claw welldeveloped; auxiliary claws small, rudimentary, or absent.The genus Pycnogonum is divided into three subgenera (Stock, 1968):1. Subgenus Pycnogonum, type species P. littorale (Stroem, 1762); oviger in malesconsists of 8–9 segments, with terminal claw.2. Subgenus Retroviger Stock, type species P. sivertseni Stock, 1955; oviger in malesconsists of 4–7 segments, terminal claw absent.3. Subgenus Nulloviger Stock, type species P. africanum Calman 1938; no ovigers inmales.Two species of the subgenus Pycnogonum have been found in the Sea of Japan.KEY TO THE SPECIES OF THE SUBGENUS PYCNOGONUM1(2). Mid-dorsal line bears tall tubercles; lateral processes smooth; proboscis narrow,with elongated apex; no auxiliary claws ............................... 1. P. tenue (p. 130)2(1). Mid-dorsal line bears very low tubercles; lateral processes bear similar lowtubercles (mostly conspicuous on 4th lateral processes); proboscis thick, withflattened apex; auxiliary claws very small ........................ *P. koreanum (p. 130)1. Pycnogonum (Pycnogonum) tenue Slater, 1879(Pl. XXIII, figs. 7–9)Slater, 1879: 283; Schimkewitsch, 1929: 15; Losina-Losinsky, 1961: 53 (Pycnogonumlittorale var. tenue); Kishida, 1927: 989, fig. 1905; Nakamura, 1987: 37, fig. 34 (Pycnogonumtenue).Description. Surface of trunk covered with small rounded tubercles. Trunkcompletely segmented. Mid-dorsal tubercles tall, armed with several short setae.Lateral processes more broad than long, separated by narrow intervals, smooth. Oculartubercle rounded; eyes pigmented, 2 anterior eyes larger than 2 posterior ones.Proboscis long, narrow, with elongated apex. Oviger 9-segmented, terminal clawcurved, longer than distal segment. Auxiliary claws absent.Geographical distribution. P. tenue occurs mainly in the East China Sea, nearthe eastern coast of Japan and in the southern part of the Sea of Japan. A subspecies P.littorale tenue (Slater) has been found in the Russian waters of the Sea of Japan.Vertical distribution. The species is distributed in depths of 27–300 m.*Pycnogonum (Pycnogonum) koreanum Kim & Stock, 1984(Pl. XXIII, figs. 10–12)Kim & Stock, 1984: 685–687, figs. 1–6; Kim & Hong, 1986: 50; Hong & Kim, 1987:161.P. koreanum was originally found in the littoral zone of Ulreung Island (on sandyground with stones). Later, it was periodically recorded on hard bottoms near theeastern, southern, and western coasts of the South Korea.130