Annual growth and age composition of the squat lobster Cervimunida johni off northern-central Chile (1996-97)

Abstract

The MULTIFAN method was used to analyse a series of monthly length-frequency distributions of the squat lobster Cervimunidajohni Porter (1903) (Galatheidae), for the estimation of growth and age composition in the fishing area off Coquimbo (29°51'S-71°22'W), in the northern-central area off Chile. Length frequency data (LFD) were collected from commercial catches made between 28°S and 32°10'S from September 1996 to September 1997. MULTIFAN distinguished 11 age classes in the LFD of males and 9 age classes in the LFD of females. This is an important result because usually only three to four age classes have been reported by analysing annual length-frequency data. Males and females were recruited to the fishery at 19.7 and 18.8 mm carapace length (CL) respectively. The von Bertalanffy growth parameters were estimated as K = 0.151 yr-1 and CL∞= 52.8 mm for males, and K = 0.174 yr-1 and CL∞ = 45.60 mm for females. Males reached larger sizes than females, which is in agreement with the growth of other Galatheids.