Realized heritability estimation on growth rate of oyster, Saccostrea cucullata Born, 1778

Abstract

A selective breeding programme for commercially important oyster species i.e. S. cucullata, Crassostrea belcheri, and C. lugubris, was initiated in October 1990 in Thailand. A base population of S. cucullata was produced in an oyster hatchery at Chulalongkorn University. They were reared at an oyster demonstration farm, Klong Prong, Angsila for almost 2 years. At 15 months the base population was separated into three groups (i.e. fast, medium and slow) based on their whole weights. They were used as broodstock to produce F 2. In November 1993, most of the F 2 reached market size. Means (± S.D.) of the whole weight of offspring produced from each group are significantly different with the values of 28.4 ± 7.84 (n = 112), 23.8 ± 8.46 (n = 83), and 20.3 ± 7.94 (n = 91) g, for fast, medium, and slow groups, respectively. This suggests that growth rate in this oyster species is heritable. In addition, survival rate of the fast group was relatively higher than but not significantly different from the other two groups. The realized heritability estimate for growth rate from this experiment was 0.277 ± 0.006, which means that mass selection, to increase S. cucullata production is very promising.