The toxicity of fifteen chemicals used in vegetation control or disease treatment was studied. The fry of largemouth black bass, Micropterus salmoides, bluegill, Lepomis macrochirus, and channel catfish, Ictalurus punctatus were used as test animals. Chemicals included were three forms of silvex, three formulations of endothal, simazine, atrazine, diquat, two forms of benzenehexachloride, roccal, acriflavine, malachite green and methylene blue. Results of toxicity tests were used to arrive at a safe concentration of the various chemicals for the species of fry used as test animals. Several of the chemicals showed evidence of species specificity and one herbicide was sufficiently toxic to these species of fishes to warrant consideration as a fish toxicant.
