D 131; A 110; P17 (ocular side), 6 (blind side); C 18; LLS 186; BR 7; GR 4+8=12; V 17+48=65.
HL 19.3% of SL; ED 24.6 (ocular side), 24.5 (blind side); BD 21.7; BW 21.8% of HL; SN 15.4; IO 9.3; UJ 36.9 (ocular side), 35.5 (blind side); LJ 43.5 (ocular side), 50.1 (blind side); CP 43.1; DH 29.2; AH 26.2; P1L 18.5 (ocular side), 15.4 (blind side); P1 base L 32.3 (ocular side), 16.9 (blind side)
Body elongate oval, thick and muscular in central portion. Head small, less than 1/5 of SL. Snout blunt and short. Eyes sinistral, small, lower eye slightly anterior to upper. Interorbital region narrow. Nostrils on ocular side closely situated each other just anterior to upper margin of lower eye, anterior nostril tubular with a long flap posteriorly, posterior nostril also tubular with a small notch posteriorly. Mouth oblique, small, both jaws about equally developed. Posterior end of upper jaw extending level of center of lower eye. Teeth small, slender conical, depressible, curved inward, arranging uniserial except on anterior part of both jaws. Dentition about equally developed on both jaws. Gill-rakers on upper limb of first arch small and short, those on lower limb flat with round tip. Fine ctenoid scales not deciduous on both ocular and blind sides. Lateral line nearly straight, running along body axis, and equally developed on both sides. Anus opening on blind side, but extremely close to ocular side.
Distribution:
Argentine Patagonia.
Remarks:
Holotype of this species is a juvnile specimen (100 mm), so further study of Achiropsetta-Mancopsetta group is needed. Pelagic young flatfish, Achiropsetta slavae newly described by Andriashev (1960) is probably attributable to A. tricolepis.
(Izumi NAKAMURA)
Distribution of Mancopsetta tricolepis in Patagonia.