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Gene flow and demographic history of the mangrove crab Neosarmatium meinerti: A case study from the western Indian Ocean

Authors :
Ragionieri, Lapo
Cannicci, Stefano
Schubart, Christoph D.
Fratini, Sara
Source :
Estuarine Coastal & Shelf Science. Jan2010, Vol. 86 Issue 2, p179-188. 10p.
Publication Year :
2010

Abstract

Abstract: Most marine organisms are characterized by at least one planktonic phase during their life history, potentially allowing interconnection of populations separated by several hundred kilometers. For many years, the idea that marine species are genetically homogenous throughout their range of distribution, due to passive larval transport, has been a paradigm. Nowadays, a growing number of studies underline the existence of boundaries in the marine realm and highlight how larval dispersal is a complex process depending on biotic as well as abiotic factors. Marine fragmented habitats, such as atolls, mangroves and estuaries, are optimal systems for investigating the marine dispersion process under a metapopulation approach, since populations can be geographically defined a priori as opposed to those occupying open marine environments. Within this frame, the present paper investigates the population genetic structure and the demographic history of the mangrove crab Neosarmatium meinerti within the western Indian Ocean by partial sequences of the mitochondrial DNA cytochrome oxidase subunit I. A total of 167 specimens were sampled from six mangrove sites distributed along the East African coast, from Kenya to South Africa, also including a mangrove forest located on Mahé Island, Seychelles. A sharp genetic break between the mainland and the Seychelles is recorded, revealing the existence of two historically distinct groups that can be defined as independent evolutionary units. Gene flow along the East African coast appears to be high enough to form a single metapopulation, probably by means of stepping stone populations. Otherwise, this mainland metapopulation is currently under expansion through a gradual moving front from the subtropical toward the equatorial populations. [Copyright &y& Elsevier]

Details

Language :
English
ISSN :
02727714
Volume :
86
Issue :
2
Database :
Academic Search Index
Journal :
Estuarine Coastal & Shelf Science
Publication Type :
Academic Journal
Accession number :
47274300
Full Text :
https://doi.org/10.1016/j.ecss.2009.11.002