Larval rearing and spat production of the great clam, Meretrix meretrix (Linnaeus)

The venerid clam Meretrix meretrix (Linnaeus) was spawned in the laboratory and for the first time the eggs were reared successfully through various stages to spat. Setting was observed on day 7 and day 10 after fertilization and was mostly completed by day 9 and 12 respectively in the two experiments. The clam seed attained an average length of 2.895 mm and height of 2.475 mm on day 75. During the rearing experiments the haptophycean flagellate, hochrysis galbana was given as food. In the light of the results obtained here the thrust areas for standardising the procedures in the hatchery production of the seed of M. meretrix are discussed