Stock assessment and potential yield of the rock shrimp, Sicyonia penicillata, fishery of Bahia Kino, Sonora, Mexico

Abstract

The rock shrimp ( Sicyonia penicillata) from the Central Gulf of California is a secondary species to the penaeid shrimp fishery. Because of decreasing yields of penaeids, the importance of rock shrimp has been growing. Analysis of data taken on board fishing vessels suggests that this resource could be exploited from January to May, but the closed season for penaeid shrimp extends from May to September. This closed season is also coincident with low abundance of penaeids. In this contribution, we assess basic parameters of the population dynamics of S. penicillata and simulate possible exploitation scenarios of rock shrimp involving some changes in the fishing season and an increase in fishing mortality. The results show that S. penicillata has a slow growth ( K/year=1.25, abdominal length, L ∞=104 mm), with a natural mortality of M/year=2.48 and continuous recruitment, with a maximum during August–October. Fishing mortality-at-length showed an exploitation pattern where higher F values corresponding to individuals 8–9 months, the average fishing mortality and average exploitation rates were F=1.58/year and F/ Z=0.36/year.