放流三疣梭子蟹月间回捕率及繁殖贡献率研究

2015年6月,将约500万只人工繁育的三疣梭子蟹C2期稚蟹放流到辽宁盘锦沿岸海域。当年7月28日—10月3日在盘锦沿岸以地笼网回捕1671只三疣梭子蟹样本,剪其螯足,剥离肌肉,提取DNA,利用微卫星DNA分子标记进行亲子鉴定,开展个体识别。试验结果显示,120只为当年放流蟹,放流后苗种短期月间放流蟹占当月回捕蟹群体的比例为2.61%~16.43%。在所检测的样本中,有22只雌性繁殖亲蟹在1671只回捕蟹群体中鉴定到其所产子代,占所检测的雌性繁殖亲蟹总样本的44%。有87只回捕到的放流蟹均来自3只雌性繁殖亲蟹,其他参与繁殖的雌性亲蟹对放流苗种的贡献率仅为0.83%~4.17%。遗传分析发现,本次增殖放流所使用的雌性繁殖亲蟹遗传多样性较高,种质质量有一定保证。上述研究成果将深化对三疣梭子蟹增殖放流的认知,为科学增殖放流提供参考。

Monthly Recapture Rate and Reproductive Contribution Rate of Released Swimming Crab

In June 2015,approximately 5 million C2 juveniles of swimming crab Portunus trituberculatus artificially bred were released into the coastal waters of Panjin,Liaoning province,and then 1671 samples of swimming crab were captured in the cage net along the coast of Panjin from July 28 th to October 3 rd of the year,and their claw were cut,muscles were stripped,and DNA was extracted to be used for paternity testing by microsatellite DNA molecular markers.It was found that 120 individuals of the released crabs had monthly recapture rate of 2.61%—16.43%.Twenty-two female samples of swimming crab were detected to have offsprings in 1671 recapture swimming crab,accounting for 44%of the total female samples examined.There were 87 recaptured crabs which were derived from 3 female stocks released,with the reproductive contribution rate of other female representing only 0.83%—4.17%.Genetic analysis indicated that the female broodstock swimming crab used in this breeding and releasing had high genetic diversity.The findings will improve understanding of the stock enhancement of swimming crab,and provide useful guidance for scientific stock enhancement of this species.