SUCCESSFUL FIRST FEEDING OF ATLANTIC HALIBUT LARVAE FROM PHOTOPERIOD-MANIPULATED BROODSTOCK

Food intake, growth, and survival were determined for larval offspring from a broodstock of Atlantic halibut Hippoglossus hippoglossus maint ained on a 6-month delayed photoperiod. The larvae were fed enriched A rtemia sp. in an indoor tank. Feeding incidence of larvae increased fr om 29.0% at 24 h to 91.4% after 4 d; the mean number of ingested Artem ia found in the larval guts was 17.7 after 24 h. The myotome height in creased significantly from 0.87 +/- 0.02 mm at release (day 0) to 1.43 +/- 0.31 mm at day 15. There was no acute mortality that could be att ributed to the transfer from yolk sac incubators, although a 20% morta lity was observed between days 3 and 6. In all, 69% of the larvae surv ived the 15-d experiment. Off-season spawning of the broodstock had no apparent negative effects on the vitality of the larvae with regard t o food intake, survival, and growth potential during the first-feeding stages. These results indicate that year-round production of juvenile halibut is feasible.