Growth Of Clam And Oyster Larvae On Different Algal Diets In A Tropical Artificial Upwelling Mariculture System1

ABSTRACT Feeding studies were conducted on larvae of Tapes japonica (Deshayes), Kumamoto oysters, Ostrea edulis Linné, and Crassostrea gigas Thunberg to evaluate different species of algae and their influence on larval growth and survival. Phytoplankton used in the studies were: Isochrysis galbana, Monochrysis lutheri, Bellerochea polymorpha, Thalassiosira pseudonana, and two unknown Cryptophyte flagellates (STX‐157 and S‐1). Larvae were obtained from spawning of adult brood stock in the controlled environment of the artificial upwelling mariculture system in St. Croix, U.S. Virgin Islands. Salinity was 34.75 to 34.95 ppt and the water temperature varied between 23 and 28 C during the experiments. Tapes japonica larvae could be successfully reared through metamorphosis on algal diets suited for growth in the tropical mariculture system on St. Croix. Mixtures of algal diets were better for growth and survival of Kumamoto larvae than unialgal diets. No significant information could be obtained from the Ostrea edulis study due to poor survival of larval cultures which may have been caused by high temperatures. Crassostrea gigas larvae grew well on a mixed diet and survival was significantly higher than that for the Kumamoto oyster larvae.