EFFECT OF TEMPERATURE ON REPRODUCTIVE DEVELOPMENT IN ARCTIC CHARR, SALVELINUS-ALPINUS (L)

1. Female broodstock Arctic charr were held at 4, 8, 12 or 16 degrees C from mid-June until late-September, and oocyte development and ovulation examined. 2. Thermal environment influenced the deposition of lipids during oocyte development, with oocytes sampled from fish held at the highest temperature containing the highest proportion of triacylglycerols and the lowest proportion of phospholipids. 3. Exposure to high temperature during the summer months resulted in ovulation being delayed by approximately 3-4 weeks. 4. The phospholipids of the ovulated eggs produced by females held at 16 degrees C contained lower proportions of the essential (n-3) fatty acids DHA and EPA than did eggs produced by females that had been exposed to lower temperatures. 5. Thermal environment did not appear to have had any marked influence on egg size, lipid class composition or the fatty acid compositions of the storage triacylglycerols.