Larvae and post-larvae of Penaeidae and Palaemonidae in coastal lagoons of the North of Rio de Janeiro (Macaé, RJ)

Abstract

The northern part of the state of Rio de Janeiro shelters many coastal lagoons, located, mostly, in the "restinga" strip that stretches from the municipality of Macaé to the municipality of Quissamã. During 1995 and 1996 samplings were made aiming to verify the diversity and density of Natantia larvae in the Imboassica, Cabiúnas and Comprida lagoons. The monthly samples were taken with a 500 µ net, in horizontal drags from a boat. In Comprida lagoon no larvae of any family of these crustaceans were found. In Cabiúnas lagoon, the autumn was the season of the year with greatest relative abundance, the larvae belonging to only one genus: Macrobrachium. In Imboassica Lagoon samples were taken in two situations related to the variation of the water level and contact with sea water: horizontal boat dragging when the sandbar (the strip of sand that separates the lagoon from the sea) was closed, larvae of Macrobrachium sp. being found, and no seasonal variation being detected, and horizontal manual dragging with open and closed sandbar conditions, in a region close to the sandbar. With the sandbar open, larvae and post-larvae of Penaeus paulensis and P. brasiliensis were found, the greatest abundances being found in the months of April/96 and May/95.