Growth performance of black tiger shrimp Penaeus monodon larvae fed diets supplemented with ulvan.

Previously, we have demonstrated the efficacy of ulvan extracted from Enteromorpha intestinalis as immunostimulant in Penaeus monodon and Litopenaeus vannamei. The present study aimed to investigate whether or not ulvan could enhance the growth performance of P. monodon larvae. Experimental diets were formulated to contain four levels of isolated ulvan, namely 0.0, 500 mg, 1,000 mg, and 1,500 mg kg and were fed to 5 replicates of shrimp larvae for 56 days. Total feed intake, specific growth rate and survival of shrimps fed ulvan-supplemented diets were all statistically similar with those fed diets with no supplementation (i.e. the control diet). Significant differences were detected in feed conversion efficiency of shrimp fed the dietary treatments but the enhancement by the ulvansupplemented diet was not very clear. In contrast, protein gained (i.e. protein productive value, PPV) of shrimps fed 1,000 mg and 1,500 mg ulvan kg diet elicited significantly higher protein productive value (PPV) than did shrimps fed the control diets, the latter dose exhibiting significantly the highest PPV. In conclusion, ulvan supplementation resulted in higher protein gain which was the benefit of dietary ulvan at least at the level of 1,000 mg kg in P. monodon larvae.