Third generation evaluation of Sydney rock oyster Saccostrea commercialis (Iredale and Roughley) breeding lines

The progeny of four breeding lines of Sydney rock oysters, Saccostrea comme rcialis, selected for faster growth over two generations, were compared wit h controls in an Is-month farming experiment. Mean whole weights of oysters from all four selection lines did not differ significantly from each other but, were significantly greater (P < 0.05) than mean whole weight of contr ols (spat produced from two groups of non-selected oyster populations). The mean increase in weight for the selection lines over the controls of 18% ( range 14-23%) after two generations of selection (third generation) compare s extremely favourably with the 4% reported previously after one generation of selection. (C) 1999 Elsevier Science B.V. All rights reserved.