Temporal variation in Engraulis anchoita eggs and larvae abundance in the Northpatagonian littoral between January-April 2001. Larval growth and mortality

Abstract

Argentine anchovy eggs and larvae abundance distribution patterns in the Argentine northpatagonian littoral during January-April 2001 were analyzed. As the season progressed, a process of decline in the reproductive activity was observed. Larval growth and mortality rates were established. Age determinations were performed analyzing otoliths daily increments. The 0.43 mm day^-1 growth rate average did not show space-time differences, fact attributed to the homogeneity of the thermal field. The 0.32 d^-1 January natural mortality rate was determined by exponential decline. Mortality rates, estimated with the mortality-aggregation model, were considered dependent on the larval size. The value ranges (d^-1) were 0.07-0.49, 0.05-0.61 and 0.07-0.51 for January, February, and March-April, respectively.