Studies on egg development and larval rearing of turbot,Scophthalmus MaximusL., and Brill,Scophthalmus RhombusL., in the laboratory

Methods are described for rearing turbot(Scophthalmus maximusL.) and brill(Scophthalmus rhombusL.) to late larval stages; the major part of the work was done on the former species. Turbot were reared to 16–0 mm and brill to 17–0 mm in length. Rearing tanks ranged in capacity from 8 to 60 1. Turbotlarvae hatched at 2–7–3–0 mm and successful first feeding was established on rotifers(Brachionus plicatilis)at a length of 3–6–3–8 mm; larvae were transferred to a diet ofArtemianauplii at 5–6—6–0 mm. Experiments on the effect of temperature on growth and yolkabsorption rates in yolksac turbot larvae showed optimal growth efficiency at 15–0 °C. Delayed initial feeding reduced subsequent survival. Drawings of larval development of turbot and brill were made as an aid to their identification in plankton samples.