INTRODUCTION Sea urchin is a marine animal of economic value. The gonad of Hemicentrotus pulcherrimus A. Agassiz and Anthocidaris crassispina A. Agassiz may be
-The development rate of Labidocera euchaeta Giesbrecht in the Xiamen Harbor was studied in laboratory. The results showed that the development times of egg and
The origin of arcuate islands and deep-sea trenches has been studied for a long time and various interpretations have been proposed. In this paper, some analyti