Biological responses to hazardous chemicals in Hydra, a Cnidarian model

Abstract

The biological responses to three hazardous chemicals, sodium nitrite (NaNO2, cadmium chloride (CdCl2) and toxaphene in Hydra magnipapillata, a Cnidarian model was investigated in the aspects of mortality, asexual reproduction and regeneration. The 24 h LC50 for NaNO2 was determined to 6 mM, for CdCl2 to 2 mg/L, and finally Toxaphene to 24 mg/L. The budding rate which represents asexual reproduction significantly decreased in 120 &#53409; of NaNO2, 480 ?/L of toxaphene, and 20 ?/L of CdCl2 after exposed for 11 days (p < 0.05). The head regeneration was prohibited at 4 mM in NaNO2 and 10 mg/L in toxaphene, but CdCl2 did not affect the head regeneration up to 1 mg/L. The biotoxicity of 3 chemicals was demonstrated at the phenotypic level in Hydra. The studies on transcriptional changes could be served for early prognosis and accurate prediction for the toxicity of environmental chemicals.