Reproductive achievement of one-year-old Pacific abalone (Haliotis discus hannai) following nine generations of selective breeding for high yield and its seedling performance

Abstract

The development of high-yielding aquatic strains represents a critical pathway for optimizing resource allocation and reducing production costs in sustainable aquaculture systems. Selective breeding serves as an effective strategy to further enhance the yield potential of cultivated organisms. In this study, we report the performance of an abalone strain (HX) that had undergone intensive mass selection for high-yield at one year of age for nine generations. Results showed that seven-month-old juvenile abalone from the HX strain (with a shell length of 34.41 ± 3.70 mm and a wet weight of 5.54 ± 1.56 g) were significantly larger (P < 0.05) than those from the control strain (with a shell length of 27.43 ± 2.56 mm and a wet weight of 2.93 ± 0.79 g). Compared to parental abalones from the control group, the larger parental abalones from the HX strain produced more oocytes with larger yolk, resulting in offspring with a significantly higher (P < 0.05) metamorphosis rate. In terms of artificial feed utilization, juvenile abalone from the HX strain spent significantly more time (P < 0.05) feeding than those from the control strain. Furthermore, the organic matter and protein contents in the mixture of residual feed and feces in the HX strain’s cultivating ponds were 25.9 % and 29.3 % lower than those in the control strain, respectively. These findings indicate that abalones from the HX strain not only exhibit improved feed consumption capacity but also possess better nutrient utilization ability.