Effects of using enriched copepod with microalgae on growth, survival, and proximate composition of giant freshwater prawn (Macrobrachium rosenbergii)

Copepods are suitable to be used as a starter feed for prawn or fish larvae in hatchery. Nowadays, farmers are still having problems sustaining growth of Macrobrachium rosenbergii production since the use of commercial diets such as micro-pallet. This study was carried out for 30 days to determine the best enrichment formula for copepods. Five dietary treatments with triplicates each were used in this study to test efficacy of enriched copepod (Oithona sp.) to M. rosenbergii larvae. The enrichments used were Tetraselmis sp., Nannochloropsis sp., mixed algae (Tetraselmis sp. and Nannochloropsis sp.), yeast (Saccharomyces cerevisiae) and micro-pallet (Dindings Shrimp Feed 2203) diet that acts as the control. Copepods were enriched twice per day (10:00 a.m. and 4:00 p.m.) at 500 mg L-1 concentration for each diet. Postlarvae were fed at 6-7% of body mass per day. The growth, survival and proximate analysis of M. rosenbergii larvae were conducted to compare effectiveness of each consecutive diet. Higher specific growth rate result of M. rosenbergii was observed when fed with copepod enriched with mixed algae 4.96 +/- 0.02% and the lowest was when fed with copepod enriched with Nannochloropsis sp. 4.58 +/- 0.03%. The greatest survival rate for M. rosenbergii was seen when fed with copepod enriched with mixed algae 95.16 +/- 1.04% compared to that fed with copepod enriched with micro-pallet 89.16 +/- 1.89%. Among used enrichments, mixed algae produced the best result compared with other enrichment, especially in the proximate analysis of the M. rosenbergii larvae. Mean value of protein, lipid, moisture and ash of M. rosenbergii were found to be 70.45 +/- 1.22%, 8.55 +/- 1.11%, 15.30 +/- 0.16%, and 9.05 +/- 0.59%, respectively. The results indicated that it is highly recommended to use copepod-enriched with mixed algae to feed giant freshwater prawn larvae (PL5 and above).