TOXICITY OF LINDANE, ATRAZINE, AND DELTAMETHRIN TO EARLY LIFE STAGES OF ZEBRAFISH (BRACHYDANIO-RERIO)

Fertilized eggs of zebrafish were exposed under flow-through conditions to several concentrations of the following pesticides: lindane 40, 80, 110, 130, and 150 μg/liter; atrazine 300, 1300, and 9100 μg/liter; deltamethrin 0.5, 0.8, and 1.2 μg/liter. Hatching, abnormalities in development (external deformations, edema, etc.), and mortality were recorded over a period of 35 days. At the end of the experiment, the body lengths of the fish were measured. Survival of juvenile fish after 35 days was reduced by increasing concentrations of all xenobiotics tested: lindane enhanced the mortality from 110 μg/liter and atrazine from 1300 μg/liter, and deltamethrin showed an effect even at the lowest test concentration (0.5 μg/liter). Other parameters were affected differently: hatching rate was reduced only by deltamethrin (from 0.8 μg/liter); lindane caused a decrease in growth (40 μg/liter) but had no effect on the other parameters. Atrazine increased the number of deformations and edema (1300 μg/liter) but did not influence hatching rate and growth. The sensitivity of the early life stages to the pesticides was compared with acute toxicity data (LC50) of adult zebrafish. The early life stages were less sensitive to lindane (118 versus 75 μg/liter). whereas in the case of atrazine (1300 versus 37,000 μg/liter) and deltamethrin (0.5 versus 2 μg/liter; 0.5 μg/liter was the lowest concentration tested) larvae were more sensitive. © 1990.