The origin and biogeographic diversification of fishes in the family Poeciliidae

Abstract

The fish subfamily Poeciliinae (sensu Parenti, 1981) is widely distributed across the Western Hemisphere and a dominant component of the fish communities of Central America. Poeciliids have figured prominently in previous studies on the roles of dispersal and vicariance in shaping current geographic distributions. Most recently, Hrbek et al. combined a DNA-based phylogeny of the family with geological models to provide a biogeographic perspective that emphasized the role of both vicariance and dispersal. Here we expand on that effort with a database enlarged in the quantity of sequence represented per species, in the number of species included, and in an enlarged and more balanced representation of the order Cyprinodontiformes. We combine a robust timetree based upon multiple fossil calibrations with enhanced biogeographic analyses that include ancestral area reconstructions to provide a detailed biogeographic history of this clade. Key features of our results are that the family originated in South America, but its major diversification dates to a later colonization of Central America. We also resolve additional colonizations among South, Central and North America and the Caribbean and consider how this reconstruction contributes to our understanding of the mechanisms of dispersal.

Fig 1. Timetree for 293 Cyprinodontiformes and outgroup taxa.

Divergence times were estimated for Pollux et al.’s [9]RAxML tree using the mcmctree program in PAML 4.4c [26] with autocorrelated rates and hard-bounded constraints. Numbered nodes correspond to the sixteen fossil calibrations described in Materials and Methods. The estimated age for Tetraodontiformes to Lophiiformes (85.0 Ma) is younger than the minimum calibration age (96.9 Ma) for this node. Family names (right) are indicated for species in the order Cyprinodontiformes. The clades Poeciliinae and Anablepidae (top) have been collapsed; an expanded view of these clades can be found in Fig 2. The full timetree is available in newick format (S1 Table).

Fig 2. Timetree and ancestral area reconstructions for Poeciliinae + Anablepidae.

Divergence times were estimated for Pollux et al.’s [9] RAxML tree using the mcmctree program in PAML 4.4c [26] with autocorrelated rates and hard-bounded constraints. Ancestral areas were reconstructed with minimum area change parsimony [32].