Date Received: 16-12-2017 / Date Accepted: 16-04-2018
This study was conducted to evaluate the effect of salinity stress shock on the growth and survival of postlarval black tiger shrimps (Penaeus monodon). The experiment consisted of 7 treatments. In five treatments for salinity stress, the shrimps taken from 20‰salinity condition were abruptly transferred to 5‰, 10‰, 15‰, 20‰, and 30‰salinity environment. In other two treatments the shrimps reared at 20‰salinity were acclimated for short time (in 3 hours) and long time (in 3 days) to 5‰salinity by adding tap water at stocking density of 2 shrimps/L . After 20 days of nursing, the water condition was in a suitable range for shrimp growth. The growth of shrimp in terms of individual length and weight by sudden salinity changes was not significantly different compared to the control, but the survival was significantly lower. The highest survival rate (98,3%) was observed in the control (20‰) and the lowest survival (60,7%) was found in the salinity shock from 20‰to 5‰. The results indicated that the survival of shrimps was adversely affected when salinity was suddenly shocked at high threshold by 10 - 15‰while the increase in salinity from 20‰to 30‰did not affect shrimp survival. Both short time and long time acclimation did not affect the shrimp survival and growth.
