The geographic scale of speciation in a marine snail with high dispersal potential
Article first published online: 11 MAY 2011
© 2011 Blackwell Publishing Ltd
Journal of Biogeography
Volume 38, Issue 6, pages 1016–1032, June 2011
How to Cite
Claremont, M., Williams, S. T., Barraclough, T. G. and Reid, D. G. (2011), The geographic scale of speciation in a marine snail with high dispersal potential. Journal of Biogeography, 38: 1016–1032. doi: 10.1111/j.1365-2699.2011.02482.x
- Issue published online: 11 MAY 2011
- Article first published online: 11 MAY 2011
- new species;
- pelagic larval dispersal;
- pelagic larval duration;
Aim We use the Stramonita haemastoma species complex (Muricidae) to investigate the geographic scale of speciation in a marine snail with a long pelagic larval duration (PLD) of 2–3 months and, consequently, high dispersal potential. We aim to: (1) delimit species within Stramonita, (2) discover the phylogenetic relationship among them, (3) map their distributions, and (4) infer the age and likely cause of speciation events.
Location Tropical intertidal of the Atlantic and eastern Pacific Oceans.
Methods We use one nuclear and two mitochondrial genes to construct a molecular phylogeny of the S. haemastoma species complex. We first test the monophyly of the genus and of the species complex, and then use statistical methods to delimit species within the complex. We incorporate information from museum collections and the literature to map distributions and to look for diagnostic morphological traits. We use fossils to date our phylogeny.
Results The genus Stramonita is monophyletic and restricted to the tropical and warm-temperate Atlantic and eastern Pacific oceans. The genus is composed of Stramonita delessertiana and six members of the S. haemastoma complex: S. haemastoma, Stramonita rustica, Stramonita floridana, Stramonita canaliculata, Stramonita biserialis and Stramonita brasiliensis (new species described herein). These species are supported by reciprocal monophyly in mitochondrial gene trees, together with independent evidence from morphology, distribution and the nuclear gene. The species are almost entirely allopatric, with only three instances of sympatry. Two species have unusually wide distributions, consistent with their long PLD; one of these is amphi-Atlantic.
Main conclusions Despite the long PLD of Stramonita, speciation has occurred within the Atlantic, both in response to barriers operating at the largest geographical scale (the width of Atlantic, but not the Amazon barrier) and at a smaller scale within the western Atlantic.