Marine Pollution Bioassay by Sea Urchin Eggs, an Attempt to Enhance Sensitivity

Abstract

To improve the previous methods of marine pollution bioassay presented by the author (Kobayashi, 1971, 1974, 1977 and 1985), especially to enhance the sensitivity, some experiments were made using two species of sea urchins, Anthocidaris crassispina and Hemicentrotus pulcherrimus. The effects of various chemicals and waters upon the eggs and embryos in respective developmental stages at first cleavage and pluteus were observed. Rates of first cleavage, pluteus stages and some anomalies of development in the test water were checked. Various anomalities, i.e. the absence of cleavage, irregular cleavage induced by polyspermy, abnormal development and cytolysis, etc., occurred sensitively in the series of experiments. The irregularity was most abundantly seen at the stage of pluteus, i.e. retarded, malformed, pre-pluteus embryos and dead embryos or larvae. This result is available for improving the bioassay of marine pollution. On the basis of these experiments, a new ranking of the sea water pollution (Ranking IV) is proposed. It is sensitive, saves the time and more simple method than the Ranking III and I (1985 and 1971).