Journal of Phylogenetics & Evolutionary Biology

Monitoring Climate Change Impact on the Genetic Population Structure: The Case of the Fivebeard Rockling (Ciliata Mustela, Linnaeus, 1758) In Its Southern Limit of Distribution

Abstract

Joana I Robalo, Cristina S Lima, Sara M Francisco, Frederico Almada, Rafael Banõn, David Villegas-Ríos and Vítor C Almada

Ciliata mustela is a marine inshore fish which occurs from central Portugal to northeastern Norway. We studied the population structure of this species using cytochrome b gene and the first intron of the nuclear S7 ribosomal protein gene and samples ranging from central Portugal to Gullmars Fjord, Sweden. We tested the following alternative hypotheses: 1) is the Portuguese population of the fivebeard rockling self-sustainable? or 2) is this population dependent on migrants from the north? We found no detectable subdivision among locations. Genetic diversity indices did not change along the study area. The data support persistence during one or several glacial cycles and a rapid expansion about 10 thousand years ago. In Portugal the populations of this species are strongly affected by climatic oscillations with severe reductions in warm years (bellow detection) and recoveries in cold years. We found that the percentage of private haplotypes is consistently lower in Portugal than in other locations. Our results support the hypothesis that the Portuguese population is mainly dependent on migrants from northern locations. We discuss the possibility of using species as C. mustella to monitor short term effects on the genetic structure of populations and their relation with climate change.