A comparison of offspring growth and survival among a wild and a selected strain of the Pacific abalone (Haliotis discus hannai) and their hybrids

The commercial breeding and cultivation of the Pacific abalone (Haliotis discus hannai) in China have experienced remarkable progress over the last three decades. Both genetic breeding programs and improvements in cultivation techniques have contributed to this advancement. However, no published data have ever distinguished the progress contributed by genetic breeding from the gross advancement. We compared the offspring growth and survival among a wild and a selected strain (AO) of the Pacific abalone (Haliotis discus hannai) and their hybrids (wild♀ × AO♂) and tried to distinguish the advancement provided by genetic breeding. The offspring metamorphosis rate, growth and survival of the selected strain of the Pacific abalone were superior to those of the wild strain. In the artificial diet feeding phase, the offspring shell growth and survival rates of the selected strain were >17% and 30% higher than those of the wild stain, respectively. In the overwintering phase, the offspring shell growth, wet weight growth and survival rates were >28%, 50% and 35% higher than those of the wild stain, respectively. Although the oocytes were from the same source, the hybrids showed a superior performance compared to the purebred wild strain, especially in the metamorphosis phase, which also indicated the progress made by the selected strain in adapting to the culturing conditions. Our results demonstrated that remarkable genetic improvement has been made and that the selected strain is much more suitable for commercial abalone breeding and cultivation in China.