Metabolic disorders in muscle of farmed Atlantic cod (Gadus morhua)

Sammendrag

Farmed Atlantic cod (Gadus morhua) derived from breeding programmes or captured breeding stocks are not yet a fully domesticated species. Nevertheless, numerous significant differences have been observed between the characteristics of farmed and wild-captured Atlantic cod. Differences that have been reported include the size and shape of the head, hepatosomatic index, skin pigmentation and discolouration in the flesh of farmed cod. Farmed cod also display mineral-induced melanin deposition in the blood vessels between the muscle segments (Cooper & Midling 2007). Both the muscle structure and storage characteristics of farmed cod differ from those observed in wild fish (Olsson, Seppola & Olsen 2007). Post-mortem degradation of the muscle has been shown to proceed faster in farmed cod than in wild cod (Ofstad, Egelandsdal, Kidman, Myklebust, Olsen & Hermanssona 1996). As the farmed and the wild cod are not yet genetically distinct, the most likely sources for these differences are environmental. In our study, we used proteome analysis and electron microscopy to investigate the physiological mechanisms that could possibly explain the phenotypic differences observed between farmed and wild cod. Increased knowledge of physiological mechanisms responsible for the differences between farmed and wild fish will be important for identifying and controlling those factors influencing product quality.