Chemical and Enzymic Comparison between Red Sea Bream Eggs with High and Low Hatchability

Abstract

Changes in chemical content and enzyme activity of red sea bream Pagrus major eggs with high hatching rates (HH) during embryogenesis were compared to the eggs with low hatching rates (LH) . Triacylglycerol contents of both LH and HH showed similar changes and fell linearly during embryogenesis. LH had lower free tyrosine, phospholipid, and phosphocreatine contents than HH between the early cleavage stage and the Kupffer's vesicles appearance stage. No significant differences between HH and LH were found in aspartate aminotransferase, creatine kinase, and alkaline phosphatase activities but LH showed significant lower alanine aminotransferase activity than HH at the embryo appearance stage. These results suggest that free tyrosine and phospholipid contents are possible criteria for estimating egg quality of red sea bream.