10 from Chile (264.0-655.5 mm SL), FAKU CP 55, 124, 430-434, 750, 751, 764.
Description:
D ]]-i, 10-12+6-7; A T, 9-12+6-7; P1 T, 13-14; P2 T, 5; GR 10+1+24-28=35-39; BR 7; X 21+14=35.
HL 23.8-26.0% of SL; ED 3.1-3.6; BD 11.8-13.8; SN 9.8-10.7; IO 4.5-5.0; UJ 10.4-11.3; CP 3.0-3.4; P1L 8.9-10.2; P2L 3.3-4.5; D1H 7.0-8.8; D2H 6.9-7.6; AH 6.7-7.5.
Body fairly elongate, compressed. Head depressed, moderate in size, 3.8-4.2 times in SL. Snout sharply pointed, long, equal to postorbital length. Mouth large, posterior end of upper jaw reaching anterior margin of eye, lower jaw more projected forward than upper jaw. Several large fangs on anterior part of upper jaw, no fangs on lower jaw, teeth on lower jaw larger than teeth on upper jaw. Minute 2 teeth on vomer. Fine uniserial teeth on palatines. Two nostrils well separated each other, anterior nostril semicircular and posterior nostril slit-like. Eye small, 7-8 times in head. Interorbital region flat and wide, its width about 2 times in snout length. A small notch on posterior margin of opercle. Gill-rakers on first arch short spinescent, a raker on corner slightly larger than others. Pseudobranchiae well developed. First dorsal fin base long. Second dorsal and anal fins short, followed by several finlets. Pectoral fin short, 2.5-2.8 times in head. Pelvic fin small, situated slightly posterior to posterior insertion of pectoral fin. Caudal fin forked. Lateral line running from posttemporal region to caudal fin base, anterior part running near dorsal profile, descending below 16th to 18th dorsal fin spines, then running on midbody to caudal fin base with slight undulation. Scales deciduous thin cycloid.
Distribution:
Temperate and cold waters of the Southern Hemisphere.
Remarks:
This species chiefly feeds on pelagic crustacians, cephalopods and fishes like anchovies, sardines, carangids and mugilids. The optimum water temperature is about 13-18℃.
(Izumi NAKAMURA)
Distribution of Thyrsites atun in Patagonia.
Gill-rakers around angle on first arch of left side.