Resumo

ARRIECHE, Dwight et al. INCI [online]. 2002, vol.27, n.11, pp.613-619. ISSN 0378-1844.

The monthly physiological condition of the brown mussel Perna perna (Bivalvia: Mytilidae) from the Morro de Guarapo, Sucre State, Venezuela, was examined according to the allometric relationships, condition index (IC), gonadic index (IG) and yield (R) in both sexes in different sexual maturity stages in a 12 month sampling period. The best correlations were observed between the allometric parameters and total length, and between shell width with shell weight. In both sexes the dry mass of soft body (gonad, muscle and remaining of somatic tissue) was at its minimum in May and December, associated with a drop in IG and higher reproductive activity. The minimum monthly values of the IG and R were obtained in May and those of IC in February, whereas maximum values for IG were observed in March, for IC in October, and for R in February, with mean annual values 15.36 ± 6.92% (IG), 18.69 ± 6.39% (IC) y 29.37 ± 6.09% (R). Statistical analyses showed differences on the IG, CI, R and gonad dry mass between months and sexual maturity stages, GI between sexes, and IG, R and dry gonad mass between length intervals. Both sexes showed yearly physiological condition index variations associated with the reproductive cycle, with the highest values occurring in female mussels. The physiological condition of the brown mussels is dependent upon endogenous factors such as continuous reproduction, food availability constrained by the upwelling and nutrient cycle. Both sexes showed high condition indexes and yield throughout the study, and suggest that resource exploitation is highest for mature mussels with a length between 60-80mm

Palavras-chave : Bivalvo; Ciclo Gonádico; Maduración Sexual; Mejillón Marrón.