Comparative allometries in growth and chemical composition of mussel (Mytilus galloprovincialis Lmk) cultured in two zones in the ria Sada (Galicia, NW Spain)

A study was carried out in two zones in the ria de Sada (Galicia, NW Spain) with mussels (Mytilus galloprovincialis Lmk) coming from the same stock and cultured in rafts, from seed sized to the first split (individuals with sizes between 15 and 65 mm), in order to evaluate a) the environmental differences in each location and b) their influence on growth (length and dry weight) and on chemical composition (protein, carbohydrates, glycogen, lipid classes, and fatty acids of total lipids). Allometric relations regarding those parameters for mussels on both locations were also determined. The mussels cultured in the inner zone (Arnela), with a higher concentration in chlorophyll a during the period studied and a smaller number of cultured mussels, present the highest performance in dry weight and a nearly doubled amount of glycogen than those in the outer one (Lorbe). There are also significant differences in saturated, monounsaturated, nonmethylene interrupted dienoic, and total fatty acids and sterols, the lowest content being shown by those cultured at Arnela. The mussel is an important dietetic source of polyunsaturated ω-3 fatty acids, as eicosapentaenoic acid and docosahexaenoic acid: both of them are beneficial for health (i.e., the treatment and prevention of cardiac ischemia). The values found range from 1 to 2% of dry weight in both locations. An indicator of the greatest importance if the product is to be used for human food is the ratio of ω-6/ω-3 fatty acids. Habitual diets with a ratio of ω-6 to ω-3 fatty acids of 12-50 are associated with a greater risk. The value observed in this study was about 0.2 in both locations

Xunta de Galicia; PROINSA

Peer reviewed

Peer Reviewed