Selection for growth in the gilthead seabream, Sparus aurata L.

Despite extensive mariculture of the gilthead seabream, Sparus aurata, in the Mediterranean basin, there are no heritability estimates for growth in this or any other cultured warm water marine teleost, and so it is unknown whether selection for faster growing fish would result in genetic improvement. In the present study, we estimated heritability for weight in the Eilat hatchery strain of S. aurata, using single-generation mass selection procedures. Down, control, up and extreme up (''jumper'') selected male groups were crossed with randomly chosen unselected females. Progeny groups were cultured in replicates under communal and separate rearing conditions. Heritability estimates for weight varied, but overall were positive and of a moderate magnitude.