Abstract

Effects of Salinity Changes on Growth Performance and Survival of Rohu Fingerlings, Labeo rohita (Hamilton, 1822)

Monjurul Islam, Dewan A Ahsan, Shankar C Mandal and Anwar Hossain

Labeo rohita was reared in laboratory condition at different salinities to observe the growth and survival. Three hundred and fifty rohu fingerlings were subjected to salinity regimes of 0, 2, 4, 6, 8, 10 and 12% for 90 days. Hundred percent survival was detected at 0 to 6% salinity while 100% mortality was recorded at 10 and 12‰ salinity. Fish showed high appetitive behavior to food between 0 to 4% salinities. Lowest feed conversion ratio was found in control group while the highest was detected at 6% salinity. On the other hand, decreasing trend of specific growth rate was observed in rohu fingerlings from 0 to 8% salinity. Similar average daily gain was found at 0 to 4% salinity. Significantly higher condition factor was found in rohu fingerlings reared at all duration at 8% salinity than those of other salinities (p<0.05). Thus the present study suggests that rohu fingerlings can be reared in coastal water with salinity of up to 6% with 100% survival rate and up to 4% salinity with similar growth rate as freshwater.