TOXICITY OF COLCHICINE TOWARDS A MARINE FISH, DICENTRARCHUS-LABRAX

1. Hematology and blood biochemistry parameters were examined in order to determine the metabolic or endocrine disturbances caused by colchi cine intoxication in sea bass (Dicentrarchus labrax) aged 1 + . The de tection of non-lethal effects of colchicine requires the use of a broa d concentration range (6.25-1020 mg l-1). 2. The 48-hr LC50, was 1020 mg l-1, a value which is close to that previously reported in the refe rence fresh water fish Brachydanio rerio. Exposure to 50 and 125 mg l- 1 colchicine for 48 hr resulted in 100% mortality one week after treat ment. 3. Colchicine involves the concomitant increase of packed cell v olume and hemoglobin concentration in whole blood, in the concentratio n range of 12.5-1020 mg l-1. 4. The activity of erythrocyte antioxidan t enzymes undergoes low amplitude variations after 48-hr exposure to c olchicine, regardless of concentration. Two days after recovery, decre ased SOD, and increased catalase and peroxidase activities were shown.