Effect of Dietary Taurine Enrichment Levels on Growth Performance, Survival and Metamorphosis of Humpback Grouper Cromileptes altivelis

The effect of feeding rotifers and Artemia enriched with taurine on the growth performance, survival and metamorphosis of humpback grouper Cromileptes altivelis larvae was investigated. Rotifers and Artemia nauplii were enriched with a commercial taurine supplement at four levels: 0 gL-1 (T-0), 1 gL-1 (T-1), 2 gL-1 (T-2), and 3 gL-1 (T-3). The larvae were fed the enriched rotifers from 2 days after hatching (DAH) to 20 DAH and enriched Artemia nauplii from 14 DAH to 60 DAH in triplicate. The growth of larvae was significantly higher in T-1 and T-2 than that of T-0. The survival rate of larvae was significantly higher in T-1, T-2 and T-3 than that of T-0. The percentage of flexion stage larvae of T-1 group was significantly higher than that of T-0 group at 15 and 20 DAH. Stage-1 larvae of metamorphosis firstly appeared in all of the groups at 30 DAH, however, at 45 DAH stage-2 larvae were significantly more abundant in T-1 than other groups. Further, at 55 DAH percentage of stage-3 larvae was significantly higher in T-1 group than that of T-3 and T-0 and thereafter (60 DAH) remained significantly higher than T-0. Therefore, the larvae fed taurine-enriched rotifers and Artemia nauplii of 1 gL-1 (T-1) showed the best growth performance, survival and metamorphosis which were significantly higher than those of other treatments (P<0.05). These results suggest that taurine is an essential nutrient for humpback grouper larvae and taurine enrichment of rotifers and Artemia is an effective method of enhancing the growth performance, survival and metamorphosis success of