メキシコ湾,カリブ海沿岸から,ブラジルのサントス付近まで(Figueiredo and Menezes, 1978)とされていたが,ラプラタ河口からは初記録と思われる。沿岸域の表層域に生息し,時には入江や潟に入る。広塩性種で,若魚群がしばしば砂浜域でみられている(Whitehead, 1973, 1977a)。
備 考:
体長9〜10cm。キューバでは産業的に重要で1975年に1,800トン漁獲されている。
(稲田伊史)
Material examined:
1 from Argentina (68.5 mm SL), FSFL EM 74.
Description:
D 15; A 18-20; P1 16; P2 8; GR (lower) 30-32.
HL 24.1% of SL; ED 5.8; BD 30.7; SN 6.0; IO 5.5; UJ 11.4; CP 11.1; P1L 21.9; P2L 10.4; PreD 49.5.
Body fusiform, strongly compressed, belly with scutes forming a distinct keel composing 10 scutes between pelvic fin and anal fin origins and 18 scutes in front of pelvic fon. Dorsal fin originating slightly anterior of mid-point to body. Pelvic fin base situated under dorsal fin base. Anal fin situated posteriorly, short and low. Upper jaw without median notch. Mouth oblique, upper jaw well developed, broad, with numerous minute teeth at its lower edge. Fairly narrow tooth plates extending back from tongue. Lower jaw extending slightly further forward than upper. On both jaws, small conical teeth forming a series. Gill-rakers slender and numerous. Hind border of gill-opening with two fleshy outgrowths. Scales cycloid. Lateral line oblique. Back and upper side of body bluish green, with faint longitudinal streaks; lower side and belly silvery. A faint dark spot behind gill-cover, fins hyaline, caudal tips and margin often dusky.
Distribution:
From Gulf of Mexico and the Carribean Sea, to near Santos, Brazil (Figueiredo and Menezes, 1978). It seems the first record from the mouth of La Plata, Argentina (Whitehead, 1973). Pelagic, in coastal waters, estuaries and lagoons; euryhaline species. Schools of small individuals are often found along sandy beaches (Whitehead, 1977a).
Remarks:
Body usually 9-10 cm SL. Commercially important species in Cuba and 1,800 tons caught in 1975. Attains 5.5 inches in the Caribbean Sea (Randall, 1968).