1998 Volume 64 Issue 2 Pages 179-184
Trace elements in the statoliths of the Japanese common squid Todarodes pacificus were analyzed with PIXE (Particle Induced X-ray Emission) to investigate the environmental fluctuations that squid encountered in the ocean. To examine the quantitative relationship between the trace elements of T. pacificus statoliths and the vertical temperature profile of squid habitat, the samples were collected from three geographical regions taking account of water temperature distribution in the Sea of Japan: cold water region, intermediate water region and warm water region. Calcium was detected from T. pacificus statoliths as the main component, and other trace elements such as chromium, manganese, iron, copper, zinc and strontium were detected. The Sr concentration was the highest among those trace elements in the statoliths. In contrast, Cr, Mn, Fe, Cu and Zn were contained at relatively low levels in the statoliths. Sr concentration in the statoliths was high in the group of the cold water region, and the intermediate water region, but was low in the group of the warm water region. It was suggested that the Sr concentration of T. pacificus statoliths could be the key to reconstructing the water region of squid habitat which is expressed by the vertical temperature profile.