Abstract
Green mussel aquaculture is increasing day by day. This culture is mostly dependent on the use of natural seed/spat while some use of spat from hatcheries is also reported. The use of hatchery spat is more convenient where spat rearing with suitable feed in in-situ environment ensure quality spat production with maximum survival. So this study was designed to determine the efficacy and suitability of indigenous microalgae (Nannochloropsis sp., Isochrysis sp. and Tetraselmis sp.) as feed for Perna viridis spat production in hatchery condition. Result shows the mean survival rate was highest in the Isochrysis sp. fed spat (71.33 ± 1.52%), although it didn’t differ significantly among dietary treatment. In case of filtration and ingestion rate, Tetraselmis sp. fed spat had the highest filtration rate of 0.997 ± 0.02 mL/spat/h where Nannochlorpsis sp. fed spat had the highest ingestion rate of 7.99 × 106 ± 1.16 cells/spat/h. In case of growth, spat fed with Isochrysis had higher shell weight (0.23 ± 0.014 g), length (9.53 ± 0.34 mm), width (4.73 ± 0.22 mm) and depth (2.08 ± 0.05 mm) where the Nannochloropsis sp. diet showed the lowest growth. However, the data were not significantly different among each other in case of shell width and depth. Similarly, spat fed with Isochrysis sp. had higher instantaneous relative growth rate (0.00541 ± 0.0007 µm/day) than other two species. The result of the study showed that, all the three selected microalga diets can significantly affect the performance of the spat of green mussel but indicated the enhanced growth with Isochrysis sp. fed larvae. The output of the study will provide a better understanding in case of appropriate food selection in case of green mussel spat to improve their production in captivity.