Main biochemical fractions of liver and muscle tissues were analyzed in sole (Solea vulgaris) from the Delta of the Ebre, a river estuary on the Catalonian coast. Two-, three-, and four- year age classes were considered. Studied parameters were water content, protein, lipid, and glycogen levels, and concentrations of some lipid families (non-esterified fatty acids, triglycerides, cholesterol, and phosphatidyl choline). Total muscle protein was observed to decrease with age. This protein decrease corresponded to structural proteins. As a consequence, the proportion of soluble protein in muscle increased with age. Most substances had a higher level in the liver, with the exception of water content. Glycogen and triglyceride muscle levels were very low, probably as a result of the capture, a stressful experience, and the subsequent hypoxia, resulting from taking the fish out of the water. |
