A rapid and simple algal toxicity test method based on the oxygen evolution by green algae Selenastrum capricornutum was developed. The effect of the toxicant on the oxygen evolution during a 6-hour incubation period was observed. After obtaining the dose-response relationship, EC50 was calculated and compared with the EC50 of a traditional algal growth test. As the sensitivity of the method developed in this study was as good as that of the traditional one, it can be applied as a rapid and easy toxicity test.

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Toxicities of insecticides to three kinds of fresh water snails were evaluated. The test organisms are Physa acuta, Semisulcospira libertina and Cipangopaludina chinensis. The fresh water snails are quite low susceptible to insecticides and LC₅₀ values of organophosphates, pyrethroids, and neonicotinoids ranged from 0.84 to >100 ppm.

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Rabbit antiserum against medaka egg yolk extract was obtained. Vitellogenin (VTG) of medaka was purified from ascites of Erexposed male medaka. Immuno-character was tested by double diffusion analysis and immuno-dot analysis. The antiserum obtained exhibited an immune-reaction with blood and ascites of Erexposed medaka (male), purified medaka VTG, and egg yolk extracts, blood and hepatocyte extracts of female medaka, but not with blood and hepatocyte extracts of male medaka or carp VTG. In double diffusion analysis, two kinds of protein in the ascites reacted to the antiserum. A few proteins other than VTG were also observed by native PAGE. The results suggest that the protein induced by E2 is not only VTG. The antiserum obtained reacted to blood of male medaka exposed to E2,p-nonylphenol or bisphenol-A. Those results were suggested that the antiserum is useful for investigating the influences of xeno-estrogens on medaka.

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Toxic chemicals released into the aquatic environment do not exist independently but coexist and they have complex and interactive effects on aquatic organisms. In some cases, it is considered that they have synergistic effects. Therefore it is very important to detect quickly and easily interactive effects of toxic chemicals in order to preserve the environment from chemical pollution. In this study, interactive effects among heavy metals and agricultural chemicals, Imidacloprid, were investigated using Daphnia magna. The data were analyzed by the method of Isobologram, where a traditional swimming inhibition test and a mobility analysis test proposed by the authors were used. The experimental results were as follows; the interactive effect of lead (Pb²⁺) vs. Cadmium (Cd²⁺) was synergistic, Cd²⁺ vs. Zinc (Zn²⁺) and Pb²⁺ vs. Zn²⁺ were antagonistic, Imidacoprid vs. Pb²⁺ was antagonistic and Imidacloprid vs. Zn²⁺ was additive. We could get a high correlation between a traditional swimming inhibition test and a new mobility inhibition test using D.magna.

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Toxic chemicals released into the aquatic environment do not exist independently but coexist and they have complex and interactive effects on aquatic organisms. In some cases, it is considered that they have synergistic effects. Therefore it is very important to detect quickly and easily interactive effects of toxic chemicals in order to preserve the environment from chemical pollution. In this study, interactive effects among heavy metals and agricultural chemicals, Imidacloprid, were investigated using Daphnia magna. The data were analyzed by the method of Isobologram, where a traditional swimming inhibition test and a mobility analysis test proposed by the authors were used. The experimental results were as follows; the interactive effect of lead (Pb²⁺) vs. Cadmium (Cd²⁺) was synergistic, Cd²⁺ vs. Zinc (Zn²⁺) and Pb²⁺ vs. Zn²⁺ were antagonistic, Imidacoprid vs. Pb²⁺ was antagonistic and Imidacloprid vs. Zn²⁺ was additive. We could get a high correlation between a traditional swimming inhibition test and a new mobility inhibition test using D.magna.

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