2002 年 50 巻 1 号 p. 117-118
The Strontium: Calcium (Sr: Ca) ratio from an otolith section of three-spined stickleback, Gasterosteus aculeatus (L.) was examined in samples taken from the Hei River mouth, and the Gensui district of Otsuchi in the coast of Iwate, Japan. The samples were analyzed using an electron probe X-ray micro analyzer (JEOLJXA 8600) . While the otolith from the Hei River showed a high Sr : Ca ratio, those from the Gensui district showed a low value and little fluctuation. We can conclude from these findings that G. aculeatus (L.) collected from the Hei River is an anadromous type, whilst G. aculeatus (L.) collected from the Gensui district is a fresh water type.