PREMETAMORPHIC ANURAN TADPOLES AS TEST ORGANISM FOR AN ACUTE AQUATIC TOXICITY ASSAY

An acute semistatic bioassay method for the evaluation of water qualit y in highly polluted river samples is described. Bufo arenarum young t adpoles as test organism were used. This anuran is a species of the na tive herpetofauna of Argentina. The technique was checked with surface water samples of Reconquista River, collected from four sites along t he low-to-high pollution gradient. The controls were run with artifici al hard water. The sensitivity of tadpoles to toxicants was checked by incubation of test animals in sublethal and lethal cadmium solutions as a standard toxicant. Mortality was registered daily for 96 h and th e results were expressed as cumulative mortality. Statistical analysis was carried out by means of a multiway factor analysis of variance wi th Bonferroni range test. Each assayed sample was chemically analyzed in order to determine the content of heavy metals, and organochlorine and organophosphorous insecticides. This bioassay did allow us to disc riminate clearly between high and low polluted samples showing a good toxicological correlation with the determined chemical profile. (C) 19 97 by John Wiley & Sons, Inc.