Effect of salinity changes on growth, survival and biochemical parameters of freshwater fish Gibelion catla (Hamilton, 1822)

Abstract

Aim: The present investigation was conducted to access the effect of salinity stress on growth performance, survival and biochemical parameters of Gibelion catla under different salinity conditions with an idea to assess the potentiality of this species in inland saline affected areas. Methodology: A 30-day-experiment was conducted in 1000 l (n=10) FRP tanks to study the effect of different salinity levels on the growth and biochemical parameters of catla species. A total of 120 fish (10.4 g) was randomly distributed into four treatments (0, 3, 6 and 9 ppt) with three replicates. The water quality parameters such as pH, temperature, nitrite, nitrate, ammonia, alkalinity and dissolved oxygen were recorded for each treatment on weekly basis, whereas fish sampling was carried out at 0th and 30th day of the experimental period to ascertain survival, weight gain, specific growth rate and feed conversion ratio of the fishes from each treatment. Results: The highest growth rate was found in control subsequently in 3 and 6 ppt and the survival rate was 96.67, 83.33, 76.67 and 0% against 0, 3, 6 and 9 ppt, respectively. The red blood cells (3.65×106 μl) and haemoglobin concentration, (8.17 gm dl-1) were also higher in control fish, followed by 3 and 6 ppt. However, white blood cells (24.40×106 μl) and glucose level (123.23 mg dl-1) were higher at 6 ppt, compared to control. Plasma protein level of fish at control (0 ppt salinity) was significantly higher than those of fish exposed to 3 and 6 ppt salinities. Interpretation: The present investigation revealed that an increase in salinity level had a significant impact on the growth and physiology of Gibelion catla. However, this species can be reared in low saline areas for some time which will not only help in the utilization of salt affected areas but will also help in the generation of employment and income.