The objective of this study was to determine the LC50 (96h) of two pesticides: Sirius® 250 SC herbicide of the pyrazosulfuron-ethyl group, and Talcord® insecticide of the permethrin group, on juvenile Litopenaeus vannamei. Shrimp total hemocyte count (THC) was also determined as an indication of physiological alterations caused by the pesticides. Juvenile shrimp (5.0 ± 0.5 g) were exposed to the following concentrations: 0, 0.1, 1.0, 10, 100 and 1000 µg L-1 Sirius® 250 SC; and 0, 0.001, 0.01, 0.1, 1.0 and 10 µg L-1 Talcord®. The Talcord® LC50 (96h) was of 0.00933 µg L-1 or 9.33 ng L-1. There were no significant changes in the THC between control and test groups. No... |