Potential yield of a rock shrimp stock, Sicyonia penicillata in the northern Gulf of California

A stock of rock shrimp Sicyonia penicillata was assessed in a fishery recen tly opened at Bahia Kino, Sonora, Mexico. An age-structured model with stoc hastic recruitment was developed, which considers growth rate, natural mort ality, and fishing mortality by age. Age groups were followed year by year with a stook-recruitment Ricker function where the seasonal recruitment pat tern was defined as well. Simulations might be interpreted as showing a sta ble population with four-year cycles, reflecting a density-dependent proces s. In 1996, fishing intensity had an apparent compensatory effect on the st ock, decreasing the amplitude of natural oscillations and maintaining the s tock at a biomass level similar to the size observed in a condition of no e xploitation. The stock was found currently underexploited. As a result of t he seasonal accessibility and the age of first-catch fishing (adult shrimp) , the stock might be capable to withstand high fishing pressure without bei ng overexploited.