Maturation, age, and growth estimation of the jumbo squid dosidicus gigas (cephalopoda: Ommastrephidae) in the central region of the gulf of california

In this study, the statolith microstructure of the jumbo squid Dosidicus gigas was used to determine age, individual growth, and changes in sexual maturity off the west coast of the central region of the Gulf of California during 2000 and 2002. The number of individuals sampled was 3,369 with a sex ratio of 1.8:1 (female to male). The size at first maturity (ML50%) in males varied between 46 cm and 56 cm, which was less than that seen in females (76-79 cm). The age of 251 squid was analyzed, and the growth of each sex was described by fitting the Gompertz and logistic models to the age-mantle length (ML) data. The Gompertz model best described the growth of the jumbo squid, and no significant differences were detected between sexes (ARSS, F = 0.73, P = 0.54). The parameters estimated for the combined data were ML∞ = 143.3 cm and g (growth coefficient at inflection point) = 0.004/y and t0 (age at inflection point) = 259.5 days. From the hatch date frequency distribution, a permanent incorporation of small individuals (ML, <55 cm) was identified in the fishing zone with 2 maximum values, one in May and another in November, suggesting that there are at least 2 cohorts in the population.