Basanta Kumar Das*,Jyotirmayee Pradhan
An experiment of 100 days duration was conducted to test the effect of Microcystis aeruginosa in Labeo rohita against Aeromonas hydrophila. The rohu fingerlings (22 ± 2 g) were fed with the experimental diets incorporated with different concentrations of M. aeruginosa @ 0 g kg-1, 0.5 g kg-1, 1 g kg-1 and 5 g kg-1. Replicate groups of fish were fed for three month daily @4% body weight. At an interval of 30 days blood and serum samples were assayed for different haematological [total erythrocyte count (TEC), total leucocyte count (TLC), haemoglobin] and biochemical [blood glucose, serum aspartate aminotransferase (AST), serum alanine aminotransferase (ALT) and alkaline phosphatase (ALP)] parameters. Significantly (p ≤ 0.05) increased haemoglobin content and TLC was observed in Microcystis treated group. It was observed that the serum AST activity was significantly (p ≤ 0.05) decreased to all the treated groups of fish as compared to control on entire assay period. Serum ALT activity was significantly (p ≤ 0.05) different to all the treated groups of fish on day 60, on day 90 and on day 10 (except group B) bacterial post challenge as compared to control. After 90 days, fish were challenged with A. hydrophila and mortality (%) was recorded up to day 10 post challenge. Highest percentage of survival (72%) was noticed in the group fed 1.0 g Microcystis kg-1 dry diet. The present study suggests that the administration of bluegreen algae, Microcystis aeruginosa supplementation diets for 100 days protects the hematological and biochemical parameters in L. rohita from A. hydrophila.