The performance of a multitrophic level bioassay battery for detecting toxic effects from 24 ( ) blind samples was evaluated. Assays performed included 1 acute toxicity using Daphnia magna, Hydra ( ) attenuata, Panagrellus redivivus, Lactuca sativa, and Allium cepa L; 2 chronic or sublethality using ( ) ( ) Hydra and Panagrellus; and 3 mutagenicity using Fluctuation Muta-ChromoPlate kit and Panagrellus redivivus. Ideally, the bioassay battery should be simple, inexpensive, and multitrophic and have ( ) wide-spectrum response to toxic substances, fast delivery results -5 days , and supplies locally available. The response of the selected core of bioassays was found to be satisfactory. Toxicity rankings, estimated by comparing the highest expected response from each sample concentration of ( ) ( ) ( ) each bioassay, were the following: for acute toxicity Allium 87% , Lactuca 86% , Daphnia 67% , Hydra ( ) ( ) ( ) ( ) 43% , and Panagrellus 38% ; for sublethality Hydra 74% and Panagrellus 70% ; and for mutagenicity ( ) ( ) Fluctuation 62% and Panagrellus 58% . The samples tested contained the following toxicants: heavy ( +5 + 2 +6 + 2 + 2 + 2 ) ( metals As , Cd , Cr , Cu , Hg , and Zn
; organics dinitrophenol, aniline, nitroquinoline, ) ( ) nonylphenol, and pentachlorophenol ; and pesticides aldrin, metolachlor, and lindane . Allium, Daphnia, and Lactuca were highly sensitive for detecting acute toxicity from copper, chromium, cadmium, mercury, pentachlorophenol, nonylphenol, nitroquinoline, aniline, aldrin, p, pЈ-DDT, lindane, and metolachlor; Hydra demonstrated high lethality for zinc, nitroquinoline, and the pesticides. Sublethality for the majority of chemicals was well detected with Hydra. Detection of mutagenicity from metals, organic compounds, and pesticides was in some cases similar and in others complementary with the Fluctuation and Panagrellus tests.