A Comparison of Food Components of Red Sea Bream (Pagrus major) Cultured in Copper Alloy (Brass) and Nylon Net Cages

Abstract

The food components of red sea bream(Pagrus major) cultured in copper alloy(brass) net(BN)and nylon net(NN) cages for nine months were investigated. The body weight was 234.9g atthe beginning of the culture(the young fish), and then 692.1g(BN group) and 549.3g(NN group)at the fish cultured for nine months(the nine-month culture fish). The moisture content of theedible portion of the fish was higher in the young fish than in the nine-month culture fish. Onthe contrary, the lipid content was higher in the latter (9.1-10.6%) than in the former (7.6%). The lipid content in the nine-month culture fish was slightly higher in the BN group comparedto the NN group. There was little difference in protein content between the young fish and thenine-month culture fish, or between the BN and NN groups. There was a slightly higher levelof copper content in the liver (5ppm in the young fish and 5-6ppm in the nine-month culturefish) compared to the edible portions (1ppm in the young fish and 3-4ppm in the nine-monthculture fish), but no difference was evident between the BN and NN groups. The prominentfatty acids were 16:0, 18:1n-9, 22:6n-3, 16:1n-7, 18:2n-6, 20:5n-3, and 18:0 in the edibleportions of the young and cultured fish. The n-3 fatty acid content was slightly richer in theBN group.