El Diario de Pontevedra : periódico liberal: Ano XLII Número 12610 - 1927 xaneiro 24

The distributions of many Northern Hemisphere organisms have been influenced by fluctuations in sea level and climatic conditions during Pleistocene interglacial periods. These cycles are associated with range contraction and refugia for northern-distributed organisms as a response to glaciers. However, lower sea levels in the tropics and sub-tropics created available habitat for expansion of the ranges of freshwater organisms. The goal of this study was to use ecological niche modeling to test the hypothesis of north to south range expansion of Vieja maculicauda associated with Pleistocene glacial cycles. Understanding the biogeography of this widespread species may help us better understand the geology and interconnectivity of Central American freshwaters. Occurrence data for V. maculicauda was based on georeferencing of all museum records of specimens recovered from FishNet2. General patterns of phylogeographic structure were assessed with mtDNA. Present day niche models were generated and subsequently projected onto paleoclimatic maps of the region during the Last Interglacial, Last Glacial Maximum, and mid-Holocene. Phylogenetic analysis of mtDNA sequence data showed no phylogeographic structure throughout the range of this widespread species. Present day niche models were congruent with the observed distribution of V. maculicauda in Central America. Results showed a lack of suitable freshwater habitat in northern Central America and Mexico during the Last Interglacial, with greatest range expansion during the Last Glacial Maximum and mid-Holocene. Results support the hypothesis of a north to south range expansion of V. maculicauda associated with glacial cycles. The wide distribution of this species compared to other closely related cichlids indicates the latter did not respond to the degree of V. maculicauda in expansion of their distributions. Future work aimed at comparisons with other species and modeling of future climatic scenarios will be a fruitful area of investigation

Paleodistribution models (a, Last Interglacial; b, Last Glacial Maximum; c, mid-Holocene) and d, present-day ecological niche model for <i>Vieja maculicauda</i>.

<p>Darker areas indicate presence in more iterations of the model and therefore the highest probability of occurrence. For the LGM model, extended coastlines are a result of lower sea levels.</p

Mismatch distributions of pairwise nucleotide differences.

<p>Mismatch distributions showed a unimodal pattern and no significant differences between observed and simulated frequencies.</p

Tissue samples of <i>V</i>. <i>maculicauda</i> used for molecular phylogenetic analyses.

<p>Museum acronyms are as follows: LSUMZ, Louisiana State University Museum of Natural Science; WAM, W.A. Matamoros; USM, University of Southern Mississippi; STRI; Smithsonian Tropical Research Institute.</p

Distribution, sampling localities, and phylogeographic results for <i>Vieja maculicauda</i>.

<p>Distribution of <i>V</i>. <i>maculicauda</i> shown in shaded area on map, including Lago Nicaragua. Dots on map represent sampling localities for specimens used in phylogenetic and haplotype analyses. Numbers beside localities on the Bayesian phylogenetic tree correspond to list of samples in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0178439#pone.0178439.t001" target="_blank">Table 1</a>; letters correspond to localities on map. Numbers in haplotype network indicate number of individuals with that haplotype; circles without numbers equal one individual. Haplotype colors correspond to geographic patterns north and south of the area of the Motagua Fault.</p

General circulation models (GCMs) tested during ENM analyses.

<p>General circulation models (GCMs) tested during ENM analyses.</p

Graph showing probability of presence based on altitude (in meters) generated in ecological niche models for <i>Vieja maculicauda</i>.

<p>Graph showing probability of presence based on altitude (in meters) generated in ecological niche models for <i>Vieja maculicauda</i>.</p