Acute toxicity assessment of Polish waste/ water with a microplate-based Hydra attenuata assay: a comparison with the MicrotoxW test

The use of Hydra attenuata in acute toxicity assessment is a potentially useful tool in waste.water biomonitoring. The purpose of this study was to compare the sensitivity of H. attenuata with the extensively used MicrotoxW test on 14 waste.water samples from the Krak´ow region South Poland.. To this end, specific morphological changes displayed by the freshwater cnidarian Hydra attenuata lethal LC50s and sublethal EC50s effects. and biolumines- cence of the marine bacteria Vibrio fisheri MicrotoxW. were compared. Clearly, the Hydra assay was the more sensitive indicator of toxicity. No relationship was found among Hydra toxicological responses and water levels of As, Cd, Co, Cu, Pb and Zn. However, it appeared that toxicity to Hydra might be due to ammonia levels. Additional studies to better circumscribe the tolerance of H. attenuata to ‘natural’ water characteristics are needed.