Impact of UV-B Radiation on the Physiology of Freshwater Carp Labeo rohita Larvae and Evaluation of UV-B Protective Properties of Seeds of Achyranthes aspera and Vitamin C

Abstract

Effect of harmful UV-B radiation and their remedial measures have been studied in Labeo rohita (rohu) larvae. Larvae were fed with four different diets: D1 and D2 contained 0.1 and 0.5 % Achyranthes aspera seeds, respectively; D3 contained 800 mg vitamin C/kg diet, and D4 contained control diet. After 50 days, all groups were exposed to UV-B radiation (80 μW/cm2). One batch of control diet-fed fish was exposed to UV-B (D4Ex), and the other group remained unexposed (D4UEx). Survival rate of rohu was significantly (P < 0.05) higher in D2 when compared to others. Among the exposed groups, highest average weight was recorded in D2 (103 ± 4 mg). Total tissue protein concentration was higher in exposed groups compared to the unexposed one. Glutamic oxaloacetic transaminase (GOT) and glutamate pyruvate transminase (GPT) levels were minimum in unexposed control diet-fed fish. Vitamin C provided protection against lipid peroxidation which was evident from the lowest level of thiobarbituric acid reactive substance in exposed fish (D3). Significantly (P < 0.05) higher nitric oxide synthase level in fish fed with Achyranthes aspera seeds (0.5 %) supplemented diet showed the immunomodulatory property of the seeds. A combination of vitamin C and seed may be more UV-B protective for carp larvae.