STUDIES ON THE EFFECTS OF SOME AGENTS ON FERTILIZED SEA URCHIN EGGS, AS A PART OF THE BASES FOR MARINE POLLUTION BIOASSAY I

Abstract

1. A few series of experiments were made to clear the effects of four factors for marine pollution, tannic acid, kaolin, pH and higher temperature, after the manual of bioassay using sea urchin eggs and embryos (Kobayashi, 1971). 2. The minimal concentration of tannic acid, the main toxic component of the extracts from timbers stored in the sea, to inhibit the fertilization, cleavage and later development of sea urchin eggs was 6.3 ppm. 3. Kaolin, the main component of clayey soil, at the concentrations over 250 ppm more or less affected the fertilization, cleavage and later development. 4. The normal fertilization and cleavages were maintained in Anthocidaris crassispina between pH 7.8 to 8.6, the neutral pH remarkably induced polyspermy, the decrease of pH below 6.6 reduced rates of fertilization and cleavage, and the increase of pH above 9.0 also brought about the reduction in fertilization and cleavage rates followed by cytolysis. 5. The raise of temperature by more than 3 degrees Centigrade above the usual summer water temperature reduced rates of fertilization and cleavage, but promoted polyspermy and cytolysis.