Strong Sexual Selection Does Not Induce Population Differentiation in a Fish Species with High Dispersal Potential: The Curious Case of the Worm Pipefish Nerophis lumbriciformis (Teleostei: Syngnathidae).

摘要: High levels of population differentiation are a common demographic pattern in syngnathids, even at small geographical scales. This is probably the end result life history traits observed within family, involving limited dispersal capabilities and strong habitat dependency. The worm pipefish, Nerophis lumbriciformis, which displays all these characteristics, also presents an additional variable potentially able to promote differentiation: high sexual selection intensity, especially extremes its distribution. Nevertheless, early pelagic stage, presumably allows for admixture, could prevent structuring. Here, we assessed phylogeography N. lumbriciformis through amplification cytochrome b, 12S, 16S rDNA mitochondrial markers as well rhodopsin nuclear marker, performed upon 119 individuals. We genetically homogeneous with indications extensive gene flow. tentatively attribute this finding potential species' larvae, supported by marine currents acting major vectors. detected signal expansion towards poles, consistent current climate change scenario. Despite marked latitudinal differences phenotype reproducing absence clear structuring suggests that phenotypic plasticity can have significant role expression selection-related traits.