Effect of combined acid sulfate and salinity on growth and survival of saline water striped catfish (Pangasianodon hypophthalmus) at the fingerling stage

Abstract

The strain of striped catfish (Pangasianodon hypophthalmus) was selected in brackish water was produced at Can Tho University to improve its tolerance to salinity. The aim of this study was to evaluate the effect of acidic sulfate water in combination with salinity on the growth performance and survival rate of selected striped catfish at the fingerling stage. The striped catfish fingerlings (15.54±0.09 g) were allocated in a completely randomized design with triplicates of nine treatments, including 3 pH levels (5.5, 6.5 and 7.5) combined with 3 salinity levels (3‰, 6‰ and 9‰). The results show that there was an interaction between pH and salinity on the growth parameters, survival and FCR of fish after 60 days of culture (p<0.05). Specifically, fish in the treatment of 6.5-3‰ had the highest weight (52.14±0.56 g) and length (18.6±0.11 cm), while the lowest was in the treatment of pH 5.5-9‰, statistically significant compared to the other treatments. Similarly, daily weight gain (DWG) and specific growth rate in weight (SGRW) were highest in the pH 6.5-3‰ treatment (p<0.05). The lowest and highest FCR were at the treatments of pH 6.5-3‰ (1.04) and 5.5-9‰ (1.8), respectively and they were significant differences among all treatments (p<0.05). There was a remarkable difference on survival rate at the treatment of pH 5.5-9‰ (p<0.05). The results suggest that acidic sulfate concentration with slightly low pH (pH 6.5) and salinity of 3‰ could be considered to be the optimal environment for saline tolerant striped catfish.