Data from: Toward responsible stock enhancement: broadcast spawning dynamics and adaptive genetic management in white seabass aquaculture

The evolutionary effects captive-bred individuals can have on wild conspecifics are necessary considerations for stock enhancement programs, but breeding protocols are often developed without knowledge of realized reproductive behavior. To help fill that gap, parentage was assigned to offspring produced by a freely-mating group of 50 white seabass (Atractoscion nobilis), a representative broadcast spawning marine finfish cultured for conservation. Similar to the well-known and closely-related red drum (Sciaenops ocellatus), A. nobilis exhibited large variation in reproductive success. More males contributed and contributed more equally than females within and among spawns in a mating system best described as lottery polygyny. Two females produced 27% of the seasonal offspring pool and female breeding effective size averaged 1.85 per spawn and 12.38 seasonally, whereas male breeding effective size was higher (6.42 and 20.87, respectively), with every male contributing 1-7% of offspring. Further, females batch spawned every 1-5 weeks, while males displayed continuous reproductive readiness. Sex-specific mating strategies resulted in multiple successful mate pairings and a breeding effective to census size ratio of ≥ 0.62. Understanding a depleted species’ mating system allowed management to more effectively utilize parental genetic variability for culture, but the fitness consequences of long-term stocking can be difficult to address.人工繁育个体对野生同种个体的进化影响，是种群增殖计划中必须考量的核心因素，但现有繁育方案的制定往往未充分结合物种实际的繁殖行为特征。为填补这一研究空白，本研究对50条用于保护繁育的典型体外受精型海水硬骨鱼——白海鲈（Atractoscion nobilis）的自由交配群体所产生的后代开展了亲权鉴定。与亲缘关系密切且广为人知的红鼓鱼（Sciaenops ocellatus）类似，白海鲈的繁殖成功率存在显著个体差异。在以抽奖式一夫多妻制为典型特征的交配系统中，各产卵批次内及批次间的雄性繁殖贡献占比更高，且贡献分布更为均衡。本季度共有2条雌性个体贡献了27%的后代群体，雌性繁殖有效种群大小在单次产卵批次中平均为1.85，全季度平均为12.38；而雄性繁殖有效种群大小显著更高，分别为6.42与20.87，每条雄性个体的后代贡献占比为1%至7%。此外，雌性个体每1至5周分批产卵一次，而雄性个体则始终处于繁殖准备状态。基于性别特异性的交配策略，本研究实现了多组成功配对，且繁殖有效种群大小与普查种群大小的比值不低于0.62。明确种群数量下降物种的交配系统，有助于管理者在繁育过程中更高效地利用亲本的遗传多样性，但长期人工放流带来的适合度后果仍难以全面评估。