Sunfish

. The uptake and release o f 2-chloro-4,6-bis(ethylamino)-5- triazine (simazine) by green sunfish (Lepomis cyanellus Raf.) were measured during a 3-week exposure to either non-labeled or sym­ metrically ring-labeled 14 C-simazine. Exposure was by feeding (3 and 10 mg/kg body wt) or bath (1 and 3 ppm). To determine the retention of simazine, treated fish remaining after exposure and sampling were placed in fresh water for 4 weeks. This water was changed weekly. Fish in the bath absorb simazine in amounts directly proportional to the concentration in the water: i.e., 0.95 and 2.29 ppm total residue after 3 weeks exposure to 1.0 and 3.0 ppm, respectively. Little or no simazine was found in feed- exposed fish 72 hr after feeding. Almost all of the residue was i n the viscera. No simazine residue was detected in fish from the water bath exposure after they had been in fres h water 7 days.