Comparison of Genetic Diversity between Hatchery-Reared and Wild Rock Bream (Oplegnathus fasciatus) Based on Microsatellite Markers and Mitochondrial COI Sequences

Hatchery release of rock bream (Oplegnathus fasciatus) is common in the Zhoushan Sea region of the East China Sea as an efficient method for stock enhancement. Clarifying the genetic effects of farm-raised populations on wild ones is important for understanding the health of fish stocks. Thus, this study collected six rock bream stocks (two wild, three hatchery-reared, and one parental) for genetic diversity analysis using microsatellite markers and mitochondrial sequences. Although the results of mitochondrial sequence analysis showed that 61.26% of the genetic diversity resided among groups, indicating a high degree of genetic differentiation among wild, hatchery-reared, and parental groups, the results of microsatellite analysis showed that 30% of the genetic diversity resided within the populations, indicating no obvious genetic differentiation among different groups. Our study suggests that though releasing hatchery-reared rock bream for stock enhancement may not noticeably decrease the genetic diversity of wild populations in the Zhoushan Sea in the short term, long-term genetic evaluations shall be taken to monitor genetic diversity in wild rock bream and ensure that the populations remain healthy.