Biometry and body chemical eomfosition of some Japanese and Eufopean fish gpecles in culture

Dissertação de mest. em Aquacultura, Unidade de Ciências e Tecnologias dos Recursos Aquáticos, Univ. do Algarve, 1997

The present study considers the relationship between total body weight and other body parameters (length and condition factor), several physiological índices (hepatosomatic índex, gonadosomatic índex, viscerosomatic índex, gut índex and visceral fat) and crude composition (moisture, fat, protein and ash) in yellowtail {Seriola quinqueradiata), amberjack {Seriola purpurascens\ red seabream {Pagrus major), seabream {Sparus aurata) and seabass {Dicentrarchus labrax). The results showed that from the regression equations determined, the weight or percentage of an organ or tissues can be estimated with a high degree of accuracy from the simple knowledge ot body weight. Relating the condition factor with body weight and the parameters with interest to the aquaculturist (percentage of dressed weight, viscerosomatic index, proportion ot visceral tat and of total body fat) in a 3D scatter plot, it was possible to observe how changes in condition, induced by the rearing conditions. affect those parameters, and, consequently, the production levei. The results showed that muscle is the principal site of fat stores in yellowtail, while for seabass, víscera appears to be the principal site, due to the great amount of fat deposited in the abdominal cavity. No conclusions could be made for the rest of the species due to the lack of significant results.