Data from: Assessing risks of invasion through gamete performance: farm Atlantic salmon sperm and eggs show equivalence in function, fertility, compatibility and competitiveness to wild Atlantic salmon

Adaptations at the gamete level (a) evolve quickly, (b) appear sensitive to inbreeding and outbreeding and (c) have important influences on potential to reproduce. We apply this understanding to problems posed by escaped farm salmon and measure their potential to reproduce in the wild. Farm Atlantic salmon (Salmo salar) are a threat to biodiversity, because they escape in large numbers and can introgress, dilute or disrupt locally adapted wild gene pools. Experiments at the whole fish level have found farm reproductive potential to be significant, but inferior compared to wild adults, especially for males. Here, we assess reproductive performance at the gamete level through detailed in vitro comparisons of the form, function, fertility, compatibility and competitiveness of farm versus wild Atlantic salmon sperm and eggs, in conditions mimicking the natural gametic microenvironment, using fish raised under similar environmental conditions. Despite selective domestication and reduced genetic diversity, we find functional equivalence in all farm fish gamete traits compared with their wild ancestral strain. Our results identify a clear threat of farm salmon reproduction with wild fish and therefore encourage further consideration of using triploid farm strains with optimized traits for aquaculture and fish welfare, as triploid fish remain reproductively sterile following escape.

配子水平上的适应性演化具备三大特征：(a) 演化速率迅捷；(b) 对近交与远交反应敏感；(c) 对物种潜在繁殖能力具有关键影响。
我们将这一认知应用于逃逸养殖大西洋鲑引发的生态问题，以评估其野外繁殖潜力。养殖大西洋鲑（Salmo salar）会对生物多样性构成威胁，因其大量逃逸后可通过基因渐渗、稀释或破坏本地适应性野生基因库。此前针对成体鲑鱼个体的实验已发现，养殖个体的繁殖潜力虽较为可观，但相较于野生成体仍显逊色，雄性个体的劣势尤为突出。
本研究通过模拟自然配子微环境，使用饲养条件一致的实验个体，开展体外（in vitro）对比实验，详细分析养殖与野生大西洋鲑精子、卵子的形态、功能、受精能力、兼容性及竞争能力，以此评估配子水平的繁殖表现。
尽管养殖种群经过定向选育且遗传多样性降低，但我们发现，养殖个体的所有配子功能性状均与野生祖先种群无显著差异。本研究结果表明，养殖鲑鱼与野生鲑鱼存在明确的杂交繁殖风险，因此应进一步考量采用兼具水产养殖优化性状与鱼类福利优势的三倍体养殖品系——此类三倍体个体逃逸后仍保持繁殖不育性。