Keywords: 
• biotoxicity /
• Brachydanio rerio /
• Vibrio Qinghaiensis /
• Xenopus tropicalis black-odor rivers /
• water quality /

Abstract: The pollution of urban black-odor rivers receives attention recently. Survey and analysis on biological toxicity of black-odor river water are necessary to identify and evaluate the water quality. In present study, biological toxicity of water in two typical black-odor rivers in Wenzhou city Jiushanwai River (JS) and Shanxia River (SX) to Brachydanio rerio Luminescent bacteria test and Xenopus tropicalis embryos were monthly detected. Results indicated that water from the two rivers was toxic to the three organisms. Toxicological effects of black-odor river water measured using mortality of zebrafish was in good agreement with measured using the relative inhibitory light rate of Luminescent bacteria. Comparatively, Luminescent bacteria were more sensitive to black-odor river water than zebrafish. In Xenopus tropicalis embryos test, toxicological effects of black-odor water were characterized by embryos survival rate and teratogenic rate. All of the three species tests showed that toxicity of SX water was higher than that of JS water, which was consistent with the black-odor degree of the rivers. Statistical analysis results of Luminescent bacteria toxicity test showed that the comprehensive toxicity of SX and JS was higher in summer from May to August than that in winter and spring. The seasonal changes of water toxicity of the black-odor rivers was closely related to temperature and dissolved oxygen values (DO) of water. The present study can provide the evidence for the bio-toxicological test of contaminative water to evaluate and treat black-odor river water.