EXPERIMENTAL STUDY ON CONTROL OF SEA URCHIN MOVEMENT AND FEEDING BY OSCILLATORY ARTIFICIAL ALGAE

Communities of algae have disappeared from the shallow waters along the Japan Sea coastline in southwest Hokkaido. A large number of studies have been made on coralline flats, it has been shown that the feeding of algae by sea urchins is an important factor affecting the formation of coralline flats.Recent investigations have shown that communities of algae form in coralline flats by removing sea urshins.The purpose of this study is to clarify the control mechanism of movement and feeding behavior of sea urchins Strongy locentrotus nudus by a oscillation of artificial algae due to wave action. It's found that sea urchins cannot climb up an artificial algae and feed fixed algae on it when the artificial algae sway an angle of more than twenty degrees.