Culture performance of different strains and crosses of the European sea bass (Dicentrarchus labrax) reared under controlled conditions at Eilat, Israel

The European sea bass (Dicentrarchus labrax) is one of the most important commercial marine fish species in the Mediterranean basin. However, broodstock domestication and selective breeding on a production scale have yet to be exploited. We reared progeny of sea bass from three different strains and their crosses throughout the entire growth cycle to market size. Data sets were analyzed to assess whether culture performance differs among different strains and crosses reared under controlled laboratory conditions using both separate and communal rearing techniques. Strains and crosses of sea bass varied significantly for traits of economic interest such as growth, survival, body composition, sex ratio, sexual maturation patterns of males, and frequencies of body shape abnormalities. Lack of evidence for substantial heterosis for growth among reciprocal crosses was also detected. Significant sexual dimorphism for length and weight was evident in all strains and crosses. At market size, the resulting weight advantages of females varied between strains and crosses; overall average weight advantage for females was about 39%. Length and weight of individual fish were strongly correlated during different time intervals. This may be useful for the choice of selection criteria, raising the possibility that the response to selection for weight at market time may be achieved by conducting selection on young fish. Generally, the results showed a high culture potential of sea bass strains originating from the southeastern areas of the Mediterranean Sea, suggesting that these domesticated strains can be exploited in future selective breeding programs.