1. Ecology of the sea urchin Strongylocentrotus nudus (A. Agassiz) at Urawa, Fukushima in southern Hokkaido;Agatsuma;Hokusuishi Geppo,1986
2. Reproductive cycle and food ingestion of the sea urchin, Strongylocentrotus nudus (A. Agassiz), in southern Hokkaido. Seasonal changes of gonad;Agatsuma;Sci Rep Hokkaido Fish Exp Stn,1988
3. Reproductive cycle and food ingestion of the sea urchin, Strongylocentrotus nudus (A. Agassiz), in southern Hokkaido, II. Seasonal changes of the gut content and test weight;Agatsuma;Sci Rep Hokkaido Fish Exp Stn,1988
4. Seasonal larval occurrence and spawning season of two sea urchins, Strongylocentrotus intermedius and S. nudus, in southern Hokkaido;Agatsuma;Sci Rep Hokkaido Fish Exp Stn,1989
5. Strongylocentrotus nudus (A. Agassiz);Agatsuma,1991