Microsatellite genotypes of Pomatoschistus microps and Pomatoschistus marmoratus of southern France lagoons

Pomatoschistus marmoratus and Pomatoschistus microps are small sedentary gobies inhabiting the lagoons of European Mediterranean and Atlantic coasts. Along the French Mediterranean coast their respective geographical distribution is not precisely known, in part because they are cryptic species. In this study, 512 gobies of both species were caught as 17 samples in 12 lagoons of the Golfe du Lion on the French Mediterranean coast. They were genotyped at six microsatellite loci and investigated statistically using multidimensional analyses, Bayesian assignment (Structure) and Newhybrids classification. This allowed us to describe the contrasted distribution of each species (P. microps in the east, P. marmoratus in the west), with several exceptions. Neither geographic structure nor isolation by distance was detected among differentiated populations of each species. The suggested mechanism is a deep sedentary behaviour associated with foundations following extinctions. The two species are sympatric or even in syntopy in 5 or 6 sampled lagoons producing rare fertile hybrids.云斑狭鳍虾虎（Pomatoschistus marmoratus）与小眼狭鳍虾虎（Pomatoschistus microps）均为小型定居性虾虎鱼，栖息于欧洲地中海与大西洋沿岸的潟湖。在法国地中海沿岸，二者各自的地理分布范围尚未得到精准界定，部分原因在于它们属于隐蔽物种。本研究于法国地中海沿岸的罗讷湾（Golfe du Lion）12处潟湖中采集了17份样本，共计512尾上述两种虾虎鱼。研究人员对所有样本的6个微卫星位点（microsatellite loci）进行了基因分型，并通过多维分析、贝叶斯归属分析（Structure）以及Newhybrids分类分析开展了统计学研究。基于上述分析，我们得以阐明两个物种截然不同的分布格局：小眼狭鳍虾虎分布于东部，云斑狭鳍虾虎分布于西部，但存在若干例外情况。在两个物种的分化种群中，均未检测到地理结构效应，也未发现距离隔离模式。研究推测其背后的机制为：两类物种均具有极强的定居习性，且种群灭绝后会重新依托原有栖息地建立种群。在5至6处采样潟湖中，两个物种同域分布甚至同微生境共存，偶尔会产生可育的杂交后代。