Effect of light intensity on survival, growth and physiology of rohu, Labeo rohita (Cyprinidae) fry

Abstract

Purpose: Light intensity is one of the important environmental factors that have strong influence on larviculture. Culture of fish at high intensity of light generates harmful radicals in the body that can compromise their health and production. The present study aims to evaluate the effect of various light intensities on the physiology of rohu Labeo rohita fry.

Materials and Methods: Rohu fry (13.56 ± 0.4 mg) were exposed at five different light intensities: 0.17 ± 0.005 (Lc, control), 1.45 ± 0.23 (L1), 2.69 ± 0.47 (L2), 3.93 ± 0.72 (L3) and 5.06 ± 0.95 Wm⁻² (L4). After 90 days of culture, rohu were harvested.

Results and Conclusions: A 2-5% mortality of rohu was recorded in L3 and L4 treatments. The average weight and specific growth rate were significantly (p < .05) higher in Lc treatment compared to others. The light intensity and swimming activity of rohu showed direct relationship, whereas, light intensity showed inverse relation with nitric oxide synthase and reduced glutathione levels. Significantly (p < .05) higher glutathione S-transferase and glutathione peroxidase activies were found in rohu exposed at L4 treatment. Higher light intensities resulted in oxidative stress in the muscles of rohu. Thiobarbituric acid reactive substances, carbonyl protein and heat shock protein 70 were significantly (p < .05) higher in rohu exposed at L4 compared to other treatments. Exposure of rohu fry to intense light resulted into physiological stress and immunosupression.

Keywords:

• Heat shock protein 70
• Labeo rohita
• light stress
• lipid peroxidation
• reduced glutathione
• swimming behavior

Disclosure statement

The authors declare that they have no conflict of interest.

Additional information

Funding

The authors are thankful to Indian Council of Agricultural Research, ICAR, New Delhi for providing financial support in the form of NFBSFARA project [AS-2001/2010-11] to carry out this study.

Notes on contributors

Nawaz Alam Khan

Nawaz Alam Khan Completed Ph.D. from University of Delhi. Area of specialization is the study of environmental impacts on aquaculture.

Arun Shivnath Ninawe

Arun Shivnath Ninawe Retired Scientific Advisor of DBT, India; Aquaculture and Marine Biotechnology expert.

JaiGopal Sharma

JaiGopal Sharma Prof. of Department of Biotechnology, Delhi Technological University. The study of impact of visible and UV-B lights on the aquatic system is area of his interest.

Rina Chakrabarti

Rina Chakrabarti Prof. of Department of Zoology, University of Delhi. The role of abiotic factors on freshwater aquaculture is one of her study areas.