Influence of sea surface temperature on reproductive period and size at maturity of brown shrimp (Farfantepenaeus californiensis) in the Gulf of California

Reproductive period and size at maturity of the brown shrimp Farfantepenaeus californiensis were analyzed for correspondence to sea surface temperature (SST) in three zones of the Gulf of California. Mature females from fishing areas in the north (Puerto Penasco), center (Guaymas), and south (Mazatlan), and monthly SST were examined. Average SST for 1983-2000 decreased from Mazatlan (26.2+/-0.2degreesC) to Puerto Penasco (22.6+/-0.3degreesC). The seasonal variation in SST between coldest and warmest months was 7.8degreesC in Mazatlan and 11.4degreesC in Puerto Penasco. The size of shrimps at maturity was inversely correlated to SST, increasing from Mazatlan (121 mm total length) to Puerto Penasco (154 mm total length). The reproductive period near Mazatlan is year-round. Guaymas and Puerto Penasco have one period of high intensity. We conclude that warmer water and low seasonal variability allow brown shrimp to reproduce more frequently, but reach smaller size at maturity.