title: Multi-locus fossil-calibrated phylogeny of Atheriniformes (Teleostei, Ovalentaria).
abstract: Phylogenetic relationships among families within the order Atheriniformes have been difficult to resolve on the basis of morphological evidence. Molecular studies so far have been fragmentary and based on a small number taxa and loci. In this study, we provide a new phylogenetic hypothesis based on sequence data collected for eight molecular markers for a representative sample of 103 atheriniform species, covering 2/3 of the genera in this order. The phylogeny is calibrated with six carefully chosen fossil taxa to provide an explicit timeframe for the diversification of this group. Our results support the subdivision of Atheriniformes into two suborders (Atherinopsoidei and Atherinoidei), the nesting of Notocheirinae within Atherinopsidae, and the monophyly of tribe Menidiini, among others. We propose taxonomic changes for Atherinopsoidei, but a few weakly supported nodes in our phylogeny suggests that further study is necessary to support a revised taxonomy of Atherinoidei. The time-calibrated phylogeny was used to infer ancestral habitat reconstructions to explain the current distribution of marine and freshwater taxa. Based on these results, the current distribution of Atheriniformes is likely due to widespread marine dispersal along the margins of continents, infrequent trans-oceanic dispersal, and repeated invasion of freshwater habitats. This conclusion is supported by post-Gondwanan divergence times among families within the order, and a high probability of a marine ancestral habitat.
authors.affiliation: Department of Biological Sciences, The George Washington University, Washington, DC, USA.
authors.forename: Daniela
authors.initials: D
authors.lastname: Campanella
authors.affiliation: Department of Biological Sciences, The George Washington University, Washington, DC, USA.
authors.forename: Lily C
authors.initials: LC
authors.lastname: Hughes
authors.affiliation: Institute for Applied Ecology, University of Canberra, Australia.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Unmack
authors.affiliation: Department of Biology, Willamette University, Salem, OR, USA.
authors.forename: Devin D
authors.initials: DD
authors.lastname: Bloom
authors.affiliation: Department of Biological Sciences, Southeastern Louisiana University, Hammond, LA, USA.
authors.forename: Kyle R
authors.initials: KR
authors.lastname: Piller
authors.affiliation: Department of Biological Sciences, The George Washington University, Washington, DC, USA. Electronic address: gorti@gwu.edu.
authors.forename: Guillermo
authors.initials: G
authors.lastname: Ortí
mesh_terms: D000818:Animals; D001499:Bayes Theorem; D005075:Biological Evolution; D005580:Fossils; D016013:Likelihood Functions; D008957:Models, Genetic; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D023701:Smegmamorpha / Q000145:classification*
keywords: Marine dispersal; Marine to freshwater transitions; Molecular clock calibration; Molecular markers; Silverside fishes; Taxonomy