Effects of light intensity and photoperiod on growth and survival of juvenile Indian white shrimps, Fenneropenaeus indicus, in laboratory conditions.

The effect of light intensity and photoperiod on growth and survival of juvenile Fenneropenaeus indicus shrimp was investigated for 40 days. After adaptation, 3 months juvenile shrimps with initial mean weight 8.13±0.20g were stocked (12 shrimps/tank) in 300 liters fiberglass tanks. Two light intensities (50 lx,1500 lx) with two photoperiods (24L/0D, 12L/12D) were provided in four treatments (50 lx, 24L/0D; 50 lx, 12L/12D; 1500 lx 24L/0D; 1500 lx, 12L/12D) useing fluorescent lamps.Water temperature and salinity were maintained between 29 and 310C and 25-26 ppt, respectively. The results indicate that maximum and minimum SGR occurred under 50 lx, 24L/0D and 1500 lx, 24L/0D, respectively(P<0.05). The treatment 50 lx, 12L/12D had the second highest SGR between treatments. However, no significant differences in SGR was found between 50 lx, 12L/12D and other treatments (P>0.05). Light intensity and photoperiod did not significantly affect survival of juvenile shrimp (P>0.05). Our study suggest that light intensity of 50 lx provide conditions for better growth rate and photoperiod could be adjusted to 12 or 24 h light.