IMPACT OF SALINITY ON THE SILURID CATFISHES: A LABORATORY INVESTIGATION

The present communication evaluates salinity tolerance of two freshwater Silurid catfishes Clarias magur and Pangasianodon hypophthalmus (Order: Siluriformes) from coastal mainland of Sundarban, India, where climate change induced salinity intrusion is a persistent phenomenon. After 100% mortality of all the fishes had been obtained from 15 to 20 g l-1 salinity levels in the first phase of the range-finding test, a non-renewal static toxicity bioassay was performed to determine the median lethal salinity (MLS-50 96h) for every fish by direct exposure to various salinities (5-18 g l-1). The MLS- 50 96h of Clarias magur and Pangasianodon hypophthalmus was found as ≈ 13 g l-1. Overall, the findings of the present study revealed that these two catfish species might be suitable for culture in the brackish water containing salinity up to 10 g l-1 and that can be encouraged in the Indian Sundarban and other tropical deltas where brackish water intrusion is a frequent phenomenon.