Abstract

Three sequential experiments were performed to assess the effect of 9 diets of traditionally used microalgae, native microalgae and artificial diets on the survival and growth rate of veliger larvae of the clam Mulinia edulis. Larvae were obtained from broodstock collected from natural banks in the Isla Grande de Chiloe, Region de Los Lagos, Chile. Diets were administrated as monospecific and mixed treatments. For traditional diets we used Isochrysis galbana (clone T) and Chaetoceros calcitrans; the mixed treatment (I. galbana/C. calcitrans) produced the greatest survival (13.6%) and daily growth rate (10.9 mu m day(-1)). The native algae used were Chlamydomona sp. and the pennate diatom identified as ND2, isolated from the water column of a natural bank and the digestive tract of M. edulis, respectively. Both, the monospecific and mixed treatments with these 2 species produced 100% mortality. The experiment with artificial diet used a paste made from the diatom ND2 (PD) and a nutrient concentrate (NC) produced in a biodigestor. The treatments with NC and NC/PD produced 100% mortality, while with PD alone survival was 0.31% and the growth rate was 1.3 mu m day(-1). The best results were obtained with a diet of the traditionally used microalgae; however, the effects of native microalgae and artificial diets should also be tested in the following stages of M. edulis, the post-larvae and seeds.