INGESTION, DIGESTION, GROWTH AND SURVIVAL OF GREEN MUSSEL Perna viridis PEDIVELIGER LARVAE FED DIFFERENT MICROALGAE

Nutrition plays a critical role in the growth and development of mussel larvae. Investigation of the appropriate algal diet for the larvae is needed to optimize production in the hatchery. In this study, three species of tropical microalgae were investigated to determine their efficacy as feed source for green mussel (Perna viridis) pediveliger (SH=256.7±5.05µm; SL=275.2±4.60µm). Pediveliger larvae (2 larvae mL^-1) were given monoalgal diets of golden brown flagellate Isochrysis galbana (Iso), diatom Chaetoceros calcitrans (Cc), and green alga Tetraselmis tetrahele (Tt) at a feeding ration of 100,000 cells mL^-1 (1:2.5:0.1 cell volume basis, respectively). Survival was high on larvae fed Iso but not significantly different from the Cc and Tt-fed larvae. Cc promoted maximum growth in terms of final shell height (SH) and shell length measurements (SL) as well as instantaneous growth rate (k). Ingestion rate was significantly high in both Cc and Iso-fed larvae, compared to larvae fed with Tt. Moreover, all diets examined were readily ingested and digested by larvae based on epifluorescence microscopy. Digestion of cells by the larvae was faster in Cc followed by Iso, then Tt algae.  The results indicate that both Iso and Cc were easily ingested and digested by the green mussel pediveliger larvae which promotes better larval performance, thus both algae are recommended as algal diets for hatchery culture of green mussel.