Technical Notes: 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 maintained on a 6-month delayed photoperiod. The larvae were fed enriched Artemia sp. inan indoor tank. Feeding incidence of larvae increased from 29.0% at 24 h to 91.4% after 4 d; the mean number of ingested Artemia found in the larval guts was 17.7 after 24 h. The myotome height increased significantly from 0.87 ± 0.02 mm at release (day 0) to1.43 ± 0.31 mm at day 15. There was no acute mortality that could be attributed to the transfer from yolk sac incubators, although a 20% mortality was observed between days 3 and 6. In all, 69% of the larvae survived the 15-d experiment. Off-season spawning of the broodstock had no apparent negative effects on the vitality of the larvae with regard to food intake, survival, and growth potential during the first-feeding stages. These results indicate that year-round production of juvenile halibut is feasible.