Growth and hatching dates of juvenile pacific sardine Sardinops caeruleus in the Gulf of California

The otolith microstructure of juvenile Pacific sardine, Sardinops caeruleus, was examined to estimate age, growth, and back-calculated hatching-date distributions. Hatching-date distributions were corrected to mortality. Juveniles were collected from the Gulf of California during February 1995, January-February and June 1996. Estimated ages of juveniles ranged from 43 to 158 days (26-105 mm SL). A Gompertz growth model provided a good description (r²=0.77) of the length-at-age relationship. The maximum calculated daily growth rate was 0.71 mm per day for 74-day-old fish. The average growth rate up to 160-days-old was 0.64 mm per day. The back-calculated hatching-date distributions showed that spawning occurs from October to April. The average birthdate distributions correspond to the beginning of the productivity cycle and consequently the growth was not limited by feeding conditions during 1995 and 1996. (C) 2000 Elsevier Science B.V.