南アメリカ北東岸沖におけるピンクスポッテッドシュリンプＰｅｎａｅｕｓ ｂｒａｓｉｌｉｅｎｓｉｓの分布と回遊

Abstract

Distribution and migration of the pink-spotted shrimp Penaeus brasiliensis off the northeastern coast of South America (Guyana-northern Brazil) were examined, based on the catch and size composition data from a trawl survey. The survey by a double-rigged shrimp trawler covered the central part of the area (off Surinam and French Guiana) and consisted of five cruises during 1981-1983. In each cruise, trawl operations were made at night at about 80 pre-determined stations.Pink-spotted shrimp was dominant in the shrimp catches, followed by southern brown shrimp P. subtilis. In all cruises, the catches of pink-spotted shrimp were confined to the outer part of the continental shelf. The mean sizes for both sexes were around 15cm (total length) at the westernmost stations and increased gradually from west to east with a tendency that larger animals occurred in the shallower part.So, it is estimated that the species may be recruited from Guyana and move eastwards on the outer part of the continental shelf off Surinam and French Guiana. It is further suggested that the spawning ground may widely spread over the most part of the distribution area off Surinam and French Guiana and that the eggs and larvae are possibly transported to Guyana by the South Equatorial Current running westwards.