DIET AND FEEDING REGIMENS FOR LARVAL DOUGHBOY SCALLOPS, MIMACHLAMYS ASPERRIMA

Nine microalgar species commonly cultured as food in mariculture were assessed as food for larvae of Mimachlamys asperrima. Larvae were cult ured for seven to nine days in a shaker incubator cabinet and fed a ra nge of monospecific, binary and ternary algal diets. When fed a single algal species, the greatest increases in shell length occurred with P avlova lutheri. When fed the remaining eight algal species in combinat ion with P. lutheri, Chaetoceros calcitrans and Tahitian Isochrysis af f. galbana produced the greatest shell length increases. In both these experiments, increases in larval shell length were correlated with la rval survival. The greatest larval growth recorded in these trials was with a diet combining the three previously listed algae. To optimise the use of this ternary diet, the maximum proportion of C. calcitrans in the diet before significant reductions in growth occurred was estim ated at 44%. However, synergistic improvements in growth of larvae fed ternary diets were achieved with the inclusion of as little as 10% C. calcitrans. Larval growth decreased when the frequency with which lar vae were fed each of the three algal species in the ternary diet was r educed from daily, to diets in which six days passed before larvae rec eived each species. The concentration and storage (2-7 days) of the te rnary diet before feeding did not affect larval growth or survival, no r did the change from discontinuous (twice daily) to continuous feedin g regimens. (C) 1997 Elsevier Science B.V.