Effects of salinity changes on growth performance and survival of climbing perch, anabas testudineus (Bloch, 1795)

Abstract

An experiment was carried out at aquatic laboratory, Department of Fisheries, University of Dhaka, Bangladesh in order to find out the salinity tolerance capability and growth performance of climbing perch (Anabas testudineus, Bloch 1795)”. There were four hundred (400) of A. testudineus fingerlings collected from a reputable fish hatchery in Mymensingh of Bangladesh. Their length and weight ranged between 1.2 to 5.5 cm and 1.07 to 7.8 g respectively. A. testudineus commonly cultured fish in Bangladesh was reared in laboratory condition at different salinities of 0, 3, 6, 9, 12, 15, 18 and 21‰ for 60 days. Hundred percent survivals were detected at 0, 3, 6 and 9‰ salinity while 100% mortality was recorded at 18 and 21‰ salinity. Variable behavioral responses to threat and feeding were observed among the fish in different treatments. Variable levels in different growth parameters were found during the study period. Lowest feed conversion ratio was found in control group while the highest was detected at 15‰ salinity. On the other hand, decreasing trend of specific growth rate and average growth rate was observed in A. testudineus fingerlings from 0 to 15‰ salinity. Significantly higher specific growth rate and average growth rate was detected in A. testudineus fingerlings reared at (0-6) ‰ salinity (p<0.05). The specific growth rate was 1.16 ± 0.05a, 0.99 ± 0.00b and 0.96 ± 0.01b at 0, 3 and 6‰ salinity respectively. The average growth rate was 0.14 ± 0.01a, 0.12 ± 0.02ab and 0.12 ± 0.01ab at 0, 3 and 6‰ salinity respectively. Thus the present study suggests that A. testudineus fingerlings can be reared in coastal water with salinity up to 6‰ as similar growth rate of freshwater.