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ALLOPATRIC DIVERGENCE AND SPECIATION IN CORAL REEF FISH: THE THREE‐SPOT DASCYLLUS, DASCYLLUS TRIMACULATUS, SPECIES COMPLEX
Author(s) -
Leray Matthieu,
Beldade Ricardo,
Holbrook Sally J.,
Schmitt Russell J.,
Planes Serge,
Bernardi Giacomo
Publication year - 2010
Publication title -
evolution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.84
H-Index - 199
eISSN - 1558-5646
pISSN - 0014-3820
DOI - 10.1111/j.1558-5646.2009.00917.x
Subject(s) - allopatric speciation , biology , coral reef , ecology , sympatry , coral reef fish , genetic divergence , species complex , ecological speciation , pomacentridae , genetic algorithm , sympatric speciation , pelagic zone , phylogeography , sebastes , population , evolutionary biology , zoology , genetic diversity , fishery , genetic variation , phylogenetics , gene flow , phylogenetic tree , gene , biochemistry , demography , sociology , fish <actinopterygii>
Long pelagic larval phases and the absence of physical barriers impede rapid speciation and contrast the high diversity observed in marine ecosystems such as coral reefs. In this study, we used the three‐spot dascyllus ( Dascyllus trimaculatus ) species complex to evaluate speciation modes at the spatial scale of the Indo‐Pacific. The complex includes four recognized species and four main color morphs that differ in distribution. Previous studies of the group using mitochondrial DNA revealed a noncongruence between color morphs and genetic groupings; with two of the color morphs grouped together and one color morph separated into three clades. Using extensive geographic sampling of 563 individuals and a combination of mitochondrial DNA sequences and 13 nuclear microsatellites, we defined population/species boundaries and inferred different speciation modes. The complex is composed of seven genetically distinct entities, some of which are distinct morphologically. Despite extensive dispersal abilities and an apparent lack of barriers, observed genetic partitions are consistent with allopatric speciation. However, ecological pressure, assortative mating, and sexual selection, were likely important during periods of geographical isolation. This study therefore suggests that primarily historical factors later followed by ecological factors caused divergence and speciation in this group of coral reef fish.