Response of a freshwater air-breathing fish, Clarias batrachus to salinity stress: an experimental case for their farming in brackishwater areas in Andaman, India

Abstract

The study was conducted to assess the effects of salinity on growth and biochemical composition of freshwater catfish, Clarias batrachus. A static nonrenewable acute toxicity bioassay test was conducted and LC 50 of salinity for 96-h exposure to the fingerling (14.5 cm) was 12.52 %. Based on these results, two sublethal salinity levels, viz. 4 and 8 % were selected to study the long-term effects of salinity on C. batrachus for a period of 90 days. From the study, it was found that growth and survival rate were less in saline water (4 and 8 %). Maximum growth and survival were recorded in freshwater (0 % salinity) and subsequently at 4 and 8 %. To assess the biochemical alteration, few important biomarkers were estimated. At the end of 90 days rearing period, glucose level in the brain and blood of C. batrachus was found to decrease with salinity. The level of liver and muscle glycogen in the fish reared at 4 % was lower than that of control. Ascorbic acid in all organs under study was found to decrease with increasing salinity, which was attributed to stress mitigation effect of vitamin C. Acetylcholine esterase (AchE) activity recorded a gradual decrease with increasing salinity. Metabolic enzymes, alkaline phosphatase (ALP) activity and adenosine triphosphosphtase (ATPase) activity also reduced both in liver and muscle tissues with increasing salinity. From the present investigation, it can be concluded that exposure to higher salinity significantly (P \ 0.01) affects the growth and physiological response of Clarias batrachus.

Striped catfish ( Pangasianodon hypophthalmus ) could be suitable for coastal aquaculture

“…A number of experiments have been conducted to evaluate the effects of salinity levels on fish physiology to find the perfect salinity level for each fish species (Boeuf & Payan, ; Enayat, Imanpoor, Shabanpoor, & Hosseini, ). It has been reported that salinity exposure significantly affected the growth of a freshwater fish Clarias batrachus (Sarma, Prabakaran, Krishnan, Grinson, & Kumar, ). Therefore, it is important to maintain the actual level of salinity to ensure a high growth rate and lower energetic cost of osmoregulation.…”

Salinity-induced changes to the survival, growth and glycogen distribution in the early fry stages of silver barb,Barbodes gonionotus(Bleeker, 1850)

“…A decrease in survival, growth and/or glycogen has also been reported for freshwater fish at elevated salinities (Britz & Hecht, ; Luz et al., ; Sarma, Prabakaran, Krishnan, Grinson, & Kumar, ). There was a significant reduction in liver glycogen in the liver of walking catfish ( Clarias batrachus ) when subjected to salinities of 4 and 8 ppt for 91 days, while survival and growth were both lower compared to those in freshwater (0 ppt) (Sarma et al., ). Meanwhile, there was a significant decrease in growth of C. auratus at 8 and 10 ppt and a slight, but not significant, reduction in their liver glycogen from 102.6 to 79.8 μg/mg at 0 and 10 ppt, respectively, after 21 days (Luz et al., ).…”

Osmoregulatory adaptations of freshwater air-breathing snakehead fish (Channa striata) after exposure to brackish water

“…Previous reports revealed that air-breathing fish, namely Monopterus albus (Pedersen et al 2014), Anabas testudineus , and Clarias batrachus (Sarma et al 2013), could survive in brackish water. Specifically, M. albus thrived in 10 ‰ salinity, while A. tesudineus tolerated up to 30 ‰.…”