Data from: A multispecies approach reveals hot-spots and cold-spots of diversity and connectivity in invertebrate species with contrasting dispersal modes

Genetic diversity is crucial for species’ maintenance and persistence, yet is often overlooked in conservation studies. Species diversity is more often reported due to practical constraints, but it is unknown if these measures of diversity are correlated. In marine invertebrates, adults are often sessile or sedentary and populations exchange genes via dispersal of gametes and larvae. Species with a larval period are expected to have more connected populations than those without larval dispersal. We assessed the relationship between measures of species and genetic diversity, and between dispersal ability and connectivity. We compiled data on genetic patterns and life history traits in nine species across five phyla. Sampling sites spanned 600 km in the northwest Mediterranean Sea and focused on a 50 km area near Marseilles, France. Comparative population genetic approaches yielded three main results. (1) Species without larvae showed higher levels of genetic structure than species with free-living larvae but the role of larval type (lecithotrophic or planktotrophic) was negligible. (2) A narrow area around Marseilles, subject to offshore advection, limited genetic connectivity in most species. (3) We identified sites with significant positive contributions to overall genetic diversity across all species, corresponding with areas near low human population densities. In contrast, high levels of human activity corresponded with a negative contribution to overall genetic diversity. Genetic diversity within species was positively and significantly linearly related with local species diversity. Our study suggests that local contribution to overall genetic diversity should be taken into account for future conservation strategies.

遗传多样性（genetic diversity）对于物种的存续与延续至关重要，但在保护生物学研究中却常被忽视。受实际条件限制，物种多样性（species diversity）的相关报道更为常见，但目前尚不明确此类多样性指标之间是否存在相关性。海洋无脊椎动物的成体多呈固着或定居生活状态，种群间借助配子与幼虫的扩散完成基因交流。具有幼虫阶段的物种，其种群间的连通性预计高于无幼虫扩散过程的物种。本研究针对物种多样性与遗传多样性的两类指标间的关联，以及扩散能力与种群连通性之间的关系展开评估。我们收集了隶属于5个门的9个物种的遗传模式与生活史性状（life history traits）数据。采样区域覆盖地中海西北部600千米范围，重点聚焦于法国马赛附近的50千米区域内。采用比较种群遗传学（comparative population genetics）方法分析后，得到三项核心结论：（1）无幼虫阶段的物种，其种群遗传结构（genetic structure）水平高于具有自由生活幼虫的物种，但幼虫类型——即卵黄营养型（lecithotrophic）或浮游营养型（planktotrophic）——的作用可忽略不计。（2）马赛附近受离岸平流（offshore advection）作用影响的狭窄区域，限制了多数物种的种群遗传连通性。（3）我们发现，在所有物种中，均存在对整体遗传多样性具有显著正向贡献的采样位点，这些位点多位于人口低密度区域附近。与之相反，人类活动强度较高的区域则对整体遗传多样性呈现负向贡献。物种种内的遗传多样性与当地物种多样性呈显著正线性相关关系。本研究表明，未来制定保护策略时，应将位点对整体遗传多样性的局部贡献纳入考量范畴。