Reproductive period and size at mass maturity of Sicyonia penicillata (Decapoda : Sicyoniidae) in Bahia Kino, Sonora, Mexico

The reproductive pattern of the rock shrimp (Sicyonia penicillata) was stud ied from January through December (1996) by sampling from boats twice a mon th (commercial shrimp fleet and one research cruise). Reproductive activity begins at 25 mm of tail length, but massive maturity or critical size is 5 5 mm of tail length. Mature organisms were found year round, but recruitmen t pattern analysis indicates that massive reproduction is from August throu gh January; a second, less intense reproductive peak, occurs in March-April . Results are coincident with the gonadical maturity analysis. A migration pattern of juveniles towards shallow areas of Bahia Kino is suggested.