春から夏にかけ南下して,沿岸域で産卵し,秋から冬にかけ北上して,沖合域へ回遊する(Hart, 1947)。一般に夜間に餌を追って浮上するが,昼間でもカタクチイワシを追って浮上することがある(Wrzesinka, 1975)。9歳で雄は56cm,雌は69cmとなる(Otero, 1977)。最大体長は95cm(Zinkevich and Sauskan, 1968)。若魚はアミ,端脚類を,成魚は魚類,イカなどを食べる。時折,とも食い現象がみられる。潜在資源量は大きく,400〜690万トンともいわれている(JAMARC, 1979c)。漁獲量は近年多く,1978年で約42万トン。
(稲田伊史)
Material examined:
34 from Argentina (163.0-550.0 mm SL, 40-221 m depth), catalogue numbers: see Inada (1981b).
Description:
D T, 9-12, 34-40; A 36-41; P1 13-16; P2 7; ORS 120-142; GR 2-5+9-12=12-16; ? 23-26+25-28=50-53; Ribs 3-4.
HL 24.4-28.0 % of SL; ED 15.5-20.7; SN 31.0-35.1; IO 24.0-28.2; UJ 47.3-52.2; P.L 15.1-21.2; P2L 11.3-16.1; PreD 28.1-31.1.
General appearance having rather short head and pectoral fin, medium sized snout, eye and gape, and large scales. Distal margin of caudal fin usually truncate, but that of smaller fish sometimes convex. Color of body silvery white.
Distribution:
Argentine hake is distributed along the east coast of the southern part of South America from about 28°S-30°S off southern Brazil to around 54°S, near the Falkland Islands. The center of abundance is in the Bonaelensis area. It mainly inhabits the continental shelf in depths between 50 m and 500 m (mainly around 200 m), at temperatures between 3.8 ℃ and 6.5 ℃ and at chlorinities between 18.4 ‰ and 18.9 ‰. It overlaps the Patagonian population of New Zealand hake (M. australis) between 49°S and 54°S.
Remarks:
This species has been confused with M. gayi and M. bilinearis by many authors, but is distinguished from M. australis in the shape of body, size of scales, number of gill-rakers and vertebrae (Marini, 1933). The tip of the pectoral fin of this species in specimens under 300-400 mm SL reaches or extends beyond the level of the anal fin origin, whereas in fish over 400 mm SL it does not reach there, although the relative length of the pectoral fin of this species is usually shorter than those of the other merlucciids.