Studying the reproductive ecology of aggregate broadcast‐spawning fishes is difficult because it is generally not feasible to sample all potential parents and unambiguously assign their offspring. We used molecular‐based parentage analysis to gain insights into the reproductive ecology of the endangered Bonytail Gila elegans and to evaluate whether protected off‐channel habitats could be used as an alternative to hatchery production. By genotyping adults and offspring (n = 4,130) that were stocked into two experimental backwaters across 3 years, we determined that most adults (82–97%) contributed to progeny production across years and backwaters, with one exception. Both sexes exhibited multiple matings, and the number of mates and family size were positively correlated. There was also a positive correlation between adult size and metrics of reproductive success. There were strong interactions between sample year and backwater, suggesting that environmental factors are the primary driver of variance in reproductive success. Knowledge of mating systems and sources of variance in reproductive success is important for management of endangered fish because high variance in reproductive success leads to substantial losses of genetic variation when few individuals reproduce successfully. Although variance in reproductive success was observed, most adults contributed to genetically diverse progeny in experimental backwaters. These results support the use of predator‐free—but otherwise natural—backwaters as an effective conservation tool for reintroducing the Bonytail to its native habitat.

中文翻译：

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凤尾鱼繁殖成功的差异是由环境因素而不是交配系统驱动的。

研究总繁殖产卵鱼类的生殖生态是困难的，因为通常不可能对所有潜在的亲本取样并明确地分配其后代。我们使用了基于分子的亲子关系分析，以深入了解濒临灭绝的Bonytail Gila elegans的生殖生态，并评估是否可以将受保护的海外栖息地用作孵化场生产的替代品。通过基因分型成人和后代（ñ （= 4,130），在3年内被放到两个实验死水中，我们确定大多数成年人（82–97％）在多年和死水中为子代生产做出了贡献，只有一个例外。男女都表现出多次交配，并且伴侣的数量和家庭规模呈正相关。成年大小与生殖成功指标之间也呈正相关。样本年与死水之间存在强烈的相互作用，这表明环境因素是生殖成功差异的主要驱动因素。繁殖成功的交配系统和变异来源的知识对于濒危鱼的管理很重要，因为繁殖成功的高度变异会导致很少有人成功繁殖时遗传变异的重大损失。尽管观察到生殖成功的差异，但大多数成年动物在实验死水中贡献了遗传多样性的后代。这些结果支持使用无捕食者（但自然除外）的死水作为将凤尾鱼重新引入其原生栖息地的有效保护工具。