V Pratheepa1, N Sukumaran. 1. Department of Aquaculture Biotechnology, Manonmaniam Sundaranar University, Sri Paramakalyani Centre for Environmental Sciences, Alwarkurchi, Tamil Nadu, India. vpratheepa@rediffmail.com
Abstract
CONTEXT: Infectious diseases are one of the major factors affecting the production of fish worldwide. The pathogens (especially bacteria) affect the immune system of fish and the administration of immunostimulants can increase resistance to infectious diseases by enhancing both specific and nonspecific defense mechanisms. OBJECTIVE: In the present study, we have conducted an experiment on the pathogen-infected Cyprinus carpio Linn. (Cyprinidae), using Euphorbia hirta Linn. (Euphorbiaceae) plant leaves as immunostimulants. MATERIALS AND METHODS: The aqueous extract of the leaves was prepared and the immunostimulant action was recorded by giving different concentrations of plant extract supplemented diet. RESULTS AND DISCUSSION: The results obtained from the studies show that the higher concentration of the extract (50 g/kg diet) provided significant immune response (specific and nonspecific) on the fish. The 50 g/kg leaf extract of E. hirta enhanced the phagocytic ratio on 10th and 15th day after the infection. The results of the specific and nonspecific immunostimulation studies are statistically significant. CONCLUSION: This work will guide the researchers for the discovery of significant aquaculture nutrients to improve the immunostimulant action on fish.
CONTEXT: Infectious diseases are one of the major factors affecting the production of fish worldwide. The pathogens (especially bacteria) affect the immune system of fish and the administration of immunostimulants can increase resistance to infectious diseases by enhancing both specific and nonspecific defense mechanisms. OBJECTIVE: In the present study, we have conducted an experiment on the pathogen-infected Cyprinus carpio Linn. (Cyprinidae), using Euphorbia hirta Linn. (Euphorbiaceae) plant leaves as immunostimulants. MATERIALS AND METHODS: The aqueous extract of the leaves was prepared and the immunostimulant action was recorded by giving different concentrations of plant extract supplemented diet. RESULTS AND DISCUSSION: The results obtained from the studies show that the higher concentration of the extract (50 g/kg diet) provided significant immune response (specific and nonspecific) on the fish. The 50 g/kg leaf extract of E. hirta enhanced the phagocytic ratio on 10th and 15th day after the infection. The results of the specific and nonspecific immunostimulation studies are statistically significant. CONCLUSION: This work will guide the researchers for the discovery of significant aquaculture nutrients to improve the immunostimulant action on fish.