Abstract
This paper reviews the literatures on toxicity bioassay for sea water and chemicals by using sea urchin eggs. The test methodologies pertaining to various stages of the life cycle, e.g. gametes (egg and sperm), fertilization and development (embryo and larva) are described. Especially, the latest method to enhance the sensitivity, by improving the previous methods of marine pollution bioassay using sea urchin eggs presented by the author (Kobayashi, 1971, 1974, 1977 and 1985 etc.), is introduced. The effects of various waters and chemicals upon the eggs and embryos in respective developmental stages at first cleavage and pluteus are observed. Rates of first cleavage, pluteus stages and some anomalies of development in the test water are examined. On the basis of these experimental results, a new ranking of the sea water pollution (Ranking IV, 1990) is proposed. The latest method is more sensitive, and simple than those in the cases of ranking I and III (1972 and 1985).
Both the results of laboratory experiments and of field assays for environmental assessment are included. With regard to the choice of the test organisms for pollution bioassay, the international use of urchins as test species is to be encouraged, because a wide and abundant distribution should be required for candidate species.
