ABSTRACT
The sea star Asterias rubens is a usefull test organism to study the effects of pollution on the coastal marine ecosystems. Recently, aberrations were found in the offspring of sea stars that had been exposed to cadmium during the reproductive cycle. A large part of the abnormalities were observed during the early cleavages. Multi-polar cleavage occurred frequently and resulted in a decrease of the number of embryos that reached the blastula stage. Similar aberrations have been found by other investigators after in vitro exposure of sea urchin eggs to toxicants and referred to as polyspermic cleavage. The abnormal cleavage can be caused by impairment of the block to polyspermy. The present study was made to investigate whether polyspermy can be induced by cadmium in the early development of A. rubens.
