Evidence of rapid adaptive trait change to local salinity in the sperm of an invasive fish
Evidence of rapid adaptive trait change to local salinity in the sperm of an invasive fish
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DOI：
10.1111/eva.12859
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发表时间：
2019-09-28
影响因子：
4.1
通讯作者：
Kvarnemo, Charlotta
中科院分区：
文献类型：
--
作者：
Green, Leon;Havenhand, Jonathan N.;Kvarnemo, Charlotta
入侵物种可能会迅速在新的环境中定居，这可能归因于表型可塑性和局部适应能力。当新环境限制入侵物种的繁殖成功时，繁殖性状预计将受到强选择。这对于将精子和卵子释放到新环境中的外部肥料来说尤其重要。尽管成年耐受高盐度，入侵鱼类Neogobius melanostomus（圆虾虎鱼）是没有从波罗的海的完全海洋区域，提高了它的分布是有限的在早期生命阶段的耐受性的可能性。在这里，我们调查的假设，传播的N。在新的盐度下，黑口鱼的精子功能受到限制。我们从波罗的海盐度较高和较低的两个入侵前沿采集精子样本，并在一系列盐度水平下对其进行测试。我们发现，精子的运动速度和精子的百分比下降的盐度水平高于和低于目前所经历的波罗的海人口，与不同的性能曲线的两个方面。精子速度也达到峰值更接近家庭的盐度条件下，在各自的入侵前，与老地方表现出更适合当地条件。通过计算精子速度如何随着世代的变化，我们发现这种表型转变在强选择下的其他鱼类的范围内，表明正在进行的局部适应或表观遗传适应他们的新环境。这些结果表明，虽然移民生殖功能障碍似乎至少部分限制了入侵N。黑口鱼在波罗的海，当地适应新的环境可能使未来的蔓延超出其目前的边界。
Invasive species may quickly colonize novel environments, which could be attributed to both phenotypic plasticity and an ability to locally adapt. Reproductive traits are expected to be under strong selection when the new environment limits reproductive success of the invading species. This may be especially important for external fertilizers, which release sperm and eggs into the new environment. Despite adult tolerance to high salinity, the invasive fish Neogobius melanostomus (round goby) is absent from fully marine regions of the Baltic Sea, raising the possibility that its distribution is limited by tolerance during earlier life stages. Here, we investigate the hypothesis that the spread of N. melanostomus is limited by sperm function in novel salinities. We sampled sperm from two invasion fronts with higher and lower salinities in the Baltic Sea and tested them across a range of salinity levels. We found that sperm velocity and percentage of motile sperm declined in salinity levels higher and lower than those currently experienced by the Baltic Sea populations, with different performance curves for the two fronts. Sperm velocity also peaked closer to the home salinity conditions in each respective invasion front, with older localities showing an increased fit to local conditions. By calculating how the sperm velocity has changed over generations, we show this phenotypic shift to be in the range of other fish species under strong selection, indicating ongoing local adaptation or epigenetic acclimation to their novel environment. These results show that while immigrant reproductive dysfunction appears to at least partly limit the distribution of invasive N. melanostomus in the Baltic Sea, local adaptation to novel environments could enable future spread beyond their current boundaries.