Larval Breeding and Commercial Scale Culture of F₁ Abalones from Selfing of and Crossing Between the Wild Population （Haliotis diversicolor） and the Cultured Population of H. diversicolor supertexta

Key words: 
• Haliotis diversicolor /
• hybridization /
• heterosis

Abstract: The growth and survival of the first generation of abalones from inbreeding of and crossing between a wild abalone（ Hailiois diversicolor） population sampled from Vietnam（ Y） and a cultured population sampled from Zhanjiang,Guangdong Province（ Z） in intensive culture conditions were compared. The results showed that there were no significant differences in fertilization rate,hatching rate and larval settlement rate（ P ＞0. 05）. However,the cross combinations showed heterosis in larval metamorphosis rate,survival rate and growth at early juvenile,late juvenile and grow-out stages as compared to the self-fertilized groups. The larval metamorphosis rates of direct crossing group YZ,reverse crossing group ZY and YY group were significantly higher than those of the ZZ group. The first generations of the two cross combinations were always significantly higher in shell length and survival rate than those of the two self-fertilized groups at juvenile and grow-out stages（ P ＜ 0. 05）.At the last sampling date 360 days after fertilization,the YZ,ZY,YY and ZZ groups had the respective shell length of（ 51. 6 ± 6. 8） mm,（ 49. 9 ± 6. 7） mm,（ 44. 3 ± 5. 4） mm and（ 41. 7 ± 4. 6） mm,and the respective survival rates of（ 87. 8 ± 5. 0） %,（ 89. 2 ± 4. 4） %,（ 54. 5 ± 2. 8） % and（ 73. 1 ± 2. 4） %. The shell length of the YY group was significantly higher than that of the ZZ group（ P ＜ 0. 05）. However,the survival rate of the YY group was lower than that of the ZZ group（ P ＜ 0. 05）. The good hetorosis and environmental adaptation of these cross combinations indicated that the cross between genetically different stocks may be an effective way for genetic improvement of small abalone H. diversicolor.