Abstract The yellowtail kingfish (Seriola lalandi) is a marine endemic fish, and a key species in the national programme for the diversification of Chilean aquaculture. Since it has been recently developed from wild fish, the biology of this species under production is to a large extent unknown. For example, the structure of the different populations used to create the national breeding programme is not well characterised. Moreover, due to the fact that it is not possible to perform stripping of broodstock in yellowtail kingfish, the genetic contributions of individuals are affected by the reproductive behaviour of this species. To increase our knowledge of the biology of this species under aquaculture conditions, the objectives of this study were: (i) to identify the population structures of wild and commercial populations of yellowtail kingfish obtained from different fisheries off the Chilean coast, and compare these to those of Mexican and Australian specimens and (ii) to study the reproductive behaviour of commercial yellowtail kingfish broodstock through paternity testing, to estimate the genetic contributions of individuals throughout the artificial spawning season in captivity. We used a set of 12 highly informative microsatellite markers optimised for paternity testing. The analysis of the population structure showed at least two clusters of yellowtail kingfish, including a single metapopulation from Chile and Australia (possibly explained by the migratory behaviour of this species in the Pacific Ocean), and the other from Mexico (which is most likely composed of California yellowtail, S. dorsalis). Some degree of admixture, albeit small, was observed between the populations from Mexico and Australia. Paternity analysis showed that the average ratio (male/female) contributing in a spawning event was 2.6, confirming the spawning behaviour observed in other species in this genus. Additionally, we observed that males participated in matings regularly during the whole spawning season. Using the results of this research, we recommend modifying the current implementation of yellowtail kingfish breeding programmes to reduce the effects of random genetic drift. This can be achieved by managing the genetic contributions of broodstock in a two-step breeding programme. This study provides useful genetic information for the long-term development and management of the Chilean yellowtail kingfish industry, which involves a species of high importance for the diversification of Chilean aquaculture.

中文翻译：

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了解孵化场生产的黄尾鰤鱼（Seriola lalandi）的种群结构和繁殖行为

摘要 黄尾鰤鱼（Seriola lalandi）是海洋特有鱼类，是智利水产养殖多样化国家计划的重点物种。由于它是最近从野生鱼类发展而来的，因此生产中的该物种的生物学在很大程度上是未知的。例如，用于创建国家育种计划的不同种群的结构没有很好地表征。此外，由于无法对黄尾鰤鱼的亲体进行剥离，个体的遗传贡献受到该物种繁殖行为的影响。为了增加我们对该物种在水产养殖条件下的生物学知识，本研究的目标是：(i) 确定从智利沿海不同渔业中获得的黄尾鰤王鱼野生和商业种群的种群结构，并将这些与墨西哥和澳大利亚标本的种群结构进行比较，以及 (ii) 通过亲子鉴定，以估计人工产卵季节中个体的遗传贡献。我们使用了一组 12 个信息丰富的微卫星标记，这些标记针对亲子鉴定进行了优化。对种群结构的分析表明，黄尾鰤鱼至少有两个集群，包括来自智利和澳大利亚的单一集合种群（可能是由于该物种在太平洋的迁徙行为），另一个来自墨西哥（最有可能由加利福尼亚黄尾鰤组成，S. dorsalis）。在来自墨西哥和澳大利亚的人群之间观察到一定程度的混合，尽管很小。亲子分析表明，产卵事件的平均比率（雄性/雌性）为 2.6，证实了在该属其他物种中观察到的产卵行为。此外，我们观察到雄性在整个产卵季节定期参与交配。使用这项研究的结果，我们建议修改黄尾鰤鱼育种计划的当前实施，以减少随机遗传漂移的影响。这可以通过在两步育种计划中管理亲体的遗传贡献来实现。