Changes in the biochemical composition of Ostrea edulis larvae fed on different food regimes

Abstract

Ostrea edulis larvae from an adult stock maintained in a raft in the Ría of Arousa (Galicia, Spain), were cultured in 1988 under four different food regimes:Pavlova lutheri, Isochrysis galbana, Phaeodactylum tricornutum andSkeletonema costatum. Growth, mortality, percentage of eyed larvae in each tank, as well as the biochemical composition of larvae at different stages of development were also studied. Protein and carbohydrate levels increase during larval development. Total lipids also increase from liberation to Day 8, and increase slightly or decrease from Day 8 to the beginning of metamorphosis. Since lipids are the main energy reserve in larvae, it is very plausible that they are being consumed during development, especially when metamorphosis begins. Data on growth, survival and biochemical composition of these larvae, which spawned 4 d after transfer of parental stock to the conditioning circuit, are compared with unpublished data on larvae from a laboratory conditioned broodstock.