Role of dissolved oxygen on behavioural and stress response of golden mahseer, Tor putitora

Abstract

Aim: The study assessed the effect of different concentration of dissolved oxygen in Tor putitora, commonly known as Golden mahseer on physiological activities of juveniles regarding their growth performance, behavioural response and stress. Methodology: Twenty-seven acclimatized fingerlings of Tor putitora were selected for the experiment, in which nine were exposed to each group of dissolved oxygen treatment (Natural, 6.76 mg l-1, low 4.81mg l-1 and high, 10.20 mg ml-1) in aquaria (60×30×30) cm. The body weight (g), cortisol concentration (ng g-1) and behaviour profile was assessed using the Ethovision XT-13 software (Noldus, Info Tech, Wageningen, The Netherlands). Results: The average value of body weight (g), cortisol concentration (ng g-1) and all behavioural profiles of Tor putitora showed a significant difference at P<0.05. The average concentration of cortisol was lower in high oxygen dissolved exposed juveniles as compared to other oxygen treatment groups. Interpretation: High oxygen content in water bodies reduces the stress level and stereotyped behavioural responses of fishes. These novel data, on cognitive swimming pattern in Tor putitora, is quite important for enhancement of production and maintaining the fish health issues. Key words: Behavioural profiling, Cortisol, Dissolved oxygen, Stress, Tor putitora