1999 Volume 16 Pages 105-109
Seasonal variation in the composition of Oyster (Crassostrea gigas) was studied. Oyster cultured in Hiroshima bay was monthly collected on April to December in 1998. Moisture was significantly increased on August to October. Glycogen content was remarkably decreased on July to October and then moderately restored. Oyster samples collected on June showed significantly higher zinc content (443 ± 63ppm) than those collected on other months (227 -329ppm). Seasonal variation was not observed in cadmium content. Difference was not observed in a ratio of soluble zinc/insoluble zinc between oyster samples collected on April and those on June. In a Sephadex G-75gel chromatography, soluble zinc of oyster collected on April was separated into two fractions while that on June was separated into three fractions. These results indicate that zinc in oyster seasonally varied in quality and quantity.
