Invasive Species Compendium

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Abstract

Seasonal differences in effect of broodstock diet on spawning success in the great scallop.

Abstract

Great scallop (Pecten maximus L.) broodstock collected at two different seasons, spring (May) and winter (December) 1997 in Norway, were given four different diets during conditioning. The spring group was spawned in late June, and the winter group in February. The highest number of veligers in the summer spawning (30 millions per 10 broodstock), was produced using a diet consisting of 80% Tahitian Isochrysis galbana. In the winter spawning, broodstock given a diet consisting of 80% diatoms (Skeletonema costatum/Chaetoceros gracilis) produced the highest number of veligers (29 millions per 10 broodstock). Fecundity and the number of egg-releasing individuals were higher in the early summer spawning (June) than in the winter spawning (February), however, the total number of three days old veligers produced was nearly the same in the two seasons.