Crescimento e fator de condição na fase juvenil de Farfantepenaeus brasiliensis (Latreille) e F. paulensis (Pérez-Farfante) (Crustacea, Decapoda, Penaeidae) em uma lagoa costeira tropical do Rio de Janeiro, Brasil

Abstract

The growth relations of the shrimps Farfantepenaeus brasiliensis (Latreille, 1817) and F. paulensis (Pérez-Farfante, 1967) were evaluated at Imboassica lagoon, Macaé, Rio de Janeiro State, between June 1995 and September 1997, in four periods after events of sandbar opening. This sandbar separated the lagoon from the Atlantic Ocean. Through the evaluation of the weight/length relationships for the two species, significant differences in each interval after the sandbar openings were observed, as much among males and females as among all individuals of the same species. The results indicated that both species presented negative allometric growth in most of the studied occasions. The frequency and abundance of the two species in the lagoon is linked to many factors, among them the season of the sandbar opening, the span of time in which the sandbar remains opened, and the presence of a reproductive stock of adults close to the area when the sandbar is open. Through the analysis of the relative condition factor (Kr), it was verified that usually the conditions inside the lagoon are favorable to the development of both species, with the exception of the occasions when the sandbar opening events happen quickly and close to each other, allowing to conclude that the sandbar openings have an influence on the growth rates and in the general status of the organisms.