Phylogeography of the California sheephead, Semicossyphus pulcher: the role of deep reefs as stepping stones and pathways to antitropicality

Ecology and Evolution

Marloes Poortvliet¹  Gary C. Longo¹  Kimberly Selkoe⁵  Paul H. Barber²  Crow White⁵  Jennifer E. Caselle⁵  Alejandro Perez-Matus⁴  Steven D. Gaines³ 

[1] Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, California;Department of Ecology and Evolutionary Biology and the Institute of the Environment and Sustainability, University of California Los Angeles, Los Angeles, California;Bren School of Environmental Science and Management, University of California, Santa Barbara, California;Subtidal Ecology Laboratory & Center for Marine Conservation, Pontificia Universidad Católica de Chile, Estación Costera de Investigaciones Marinas, Santiago, Las Cruces, Chile;Marine Science Institute, University of California Santa Barbara, Santa Barbara, California

关键词: Antitropicality;    microsatellites;    Semicossyphus;    sheephead wrasse;    speciation;    stepping stones;   

DOI  :  10.1002/ece3.840

来源: Wiley

【 摘 要 】

Abstract

In the past decade, the study of dispersal of marine organisms has shifted from focusing predominantly on the larval stage to a recent interest in adult movement. Antitropical distributions provide a unique system to assess vagility and dispersal. In this study, we have focused on an antitropical wrasse genus, Semicossyphus, which includes the California sheephead, S. pulcher, and Darwin's sheephead, S. darwini. Using a phylogenetic approach based on mitochondrial and nuclear markers, and a population genetic approach based on mitochondrial control region sequences and 10 microsatellite loci, we compared the phylogenetic relationships of these two species, as well as the population genetic characteristics within S. pulcher. While S. pulcher and S. darwini are found in the temperate eastern Pacific regions of the northern and southern hemispheres, respectively, their genetic divergence was very small (estimated to have occurred between 200 and 600 kya). Within S. pulcher, genetic structuring was generally weak, especially along mainland California, but showed weak differentiation between Sea of Cortez and California, and between mainland California and Channel Islands. We highlight the congruence of weak genetic differentiation both within and between species and discuss possible causes for maintenance of high gene flow. In particular, we argue that deep and cooler water refugia are used as stepping stones to connect distant populations, resulting in low levels of genetic differentiation.

【 授权许可】

CC BY   
© 2013 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.

Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.