COD (GADUSMORHUA ) EGG AND LARVAL QUALITY - IS BIG BEAUTIFUL?

摘要

The recent progress of industrial cod (Gadus morhua) culture is partly due to the introduction of intensive rearing techniques during the first year of life. T%e available quantity of fertilized eggs is usually enough to insure a sufficient supply. However, the quality of these gametes, i.e. their ability to give high fertilisation rates, normal embryos and larval survival and development, is less well controlled and understood. Hatching rates in commercial cod hatcheries may vary from 0 to >90%, andhigh and variable mortalities often occur during early larval development and at first feeding. At present, this is a major restraint for a reproducible production of cod juveniles. The aim of this study was to evaluate egg quality during a spawning season for cod broodstock, and to investigate whether larval behaviour reflected egg and larval quality.