The effect of stocking density on growth in the gilthead sea‐bream, Sparus aurata (L.)

Abstract

The effect of stocking density on growth and size variability in gilthead sea-bream, Sparus aurata (L.), was tested by growing juveniles at densities of 0.35 kgm−3, 1.3 kg m−3 and 3.2 kg m−3. Fish in the highest density group grew 25% slower than fish in the lowest density group. The coefficient of variation of weight (standard deviation/mean) did not change during the experiment. The effect of size variability on growth rate was tested by creating groups with coefficients of variation of weights ranging from 0.11 to 0.32, and growing them at similar density (1.5 kg m−3). No differences in growth rates between groups were found. Only the more heterogeneous group showed a large decrease in the coefficient of variation over time. It was concluded that growth in gilthead sea-bream, although negatively correlated to stocking density, did not seem to be related to intraspecific competition as assessed by changes in size variability.