Effects of light intensity, stocking density and temperature on the air-bubble disease, survivorship and growth of early juvenile seahorse Hippocampus erectus Perry, 1810

This investigation examined the effects of light intensity, stocking density and temperature on the air-bubble disease, survivorship and growth of early juveniles (2-30 days old) of seahorse Hippocampus erectus Perry. The juveniles in the 100 lx treatment had the highest air-bubble disease rate of 20.8 +/- 6.2% and the juveniles in the 500 lx treatment had the highest survival rate of 84.4 +/- 5.5%. The juvenile seahorses cultured in the 1500 lx treatment had the highest final wet weight of 0.13 +/- 0.02 g and the highest final standard length of 4.54 +/- 0.37 cm (F(7, 144)=57.406, F(7, 144)=12.315, P < 0.05). There was no significant effect of stocking density on the air-bubble disease rate (F(6, 21)=1.893, P=0.126). The juveniles cultured in the 1 ind L-1 had the highest wet weight increment of 0.134 +/- 0.031 g, but juveniles in the 2 ind L-1 had the highest standard length increment of 3.17 +/- 0.30 cm (F(6, 126)=34.902, F(6, 126)=11.726, P < 0.05), and juveniles cultured in the 1.5 ind L-1 had the highest survival rate of 86.1 +/- 4.6%. The result of interaction of light intensity and temperature showed that the juveniles cultured in the 1500 lx and 26 degrees C had the highest weight gain and specific growth rate of 3791.17 +/- 323.97% and 13.07 +/- 0.18, respectively, and the lowest air-bubble disease rate of 9.3 +/- 4.5% occurred in the 1000 lx and 26 degrees C (F(8, 36)=12.355, P < 0.05).