Phylogeographic Structure and Color Pattern Variation among Populations of Plethodon albagula on the Edwards Plateau of Central Texas
Texas populations of slimy salamanders are isolated from other members of the Plethodon glutinosus complex and are currently placed in the species P. albagula with populations from the Ozark Plateau and Ouachita Mountains of Missouri, Oklahoma, and Arkansas. We sequenced a portion of the mitochondrial protein-coding gene ND4 for 52 P. albagula from 25 localities in Texas and one locality in Missouri. Bayesian MCMC analysis identified five parapatric lineages of Plethodon in Texas. Several morphologically distinctive populations are phylogenetically embedded within the Texas radiation. Additional studies of the interactions among the lineages identified in this study will be necessary to resolve their taxonomic status.Abstract
Map showing collecting localities in Texas.
Inset map shows location in central Texas. Shaded areas with white letters show clades as labeled in Figure 3. Numbers 1–25 refer to collecting localities of specimens used in this study: 1, FM 335, 20.6 km S of intersection of FM 335 and State Hwy 41; 2, FM 337, outside Blue Oak Ranch; 3, Can Creek Cave #2; 4, 10 km S of Hunt, on S side of Hwy 39, 15 m up a draw; 5, Cherry Creek Ranch, entrance to Antonio's Cave; 6, Grand Column Cave; 7, Washington Cave; 8, Low Priority Cave; 9, Wonder World Cave; 10, Rattlesnake Cave; 11, Fern Bank Spring; 12, T-Cave; 13, Lake Austin, Apache Shores; 14, S. Shore Colorado River at Red Bud Isles; 15, Brackenridge Field Lab; 16, 2609 Westover, Austin; 17, Reed Park, Tarryhollow Drive and Pecos Street, Austin; 18, 3-Holer Cave, Spicewood Springs Road at Mesa Drive; 19, Chaos Cave; 20, Treasure Cave; 21, Tweedledum Cave; 22, Lunch Counter Cave; 23, Violet Cave; 24, Buchanan Cave; 25, Bear Spring. Numbers 26 and 27 show the location of two questionable sight records that form the basis of county records reported by Dixon (2000; see text): 26, Glory Cave; 27, Chicken Cave.
Photos comparing the range of morphological variation in Texas populations of the Plethodon glutinosus complex.
(A) Spotted morph from Real County, representative of Group D (most Group E populations also have a similar pattern); (B) morph with white lateral stripe from Hays County, representative of Group C (most Group B populations also have a similar pattern; this is the phenotype that Grobman [1944] described as representative of P. g. albagula); (C) unspotted morph from Fort Hood, representative of Group A.
Bayesian phylogenetic analysis of populations of P. albagula and related species, based on an analysis of ND4 sequences.
Support values at nodes are Bayesian posterior probabilities.
Contributor Notes
(ABB, JKK, JRR, CEP, MJM, DMH) SECTION OF INTEGRATIVE BIOLOGY AND CENTER FOR COMPUTATIONAL BIOLOGY AND BIOINFORMATICS, UNIVERSITY OF TEXAS, AUSTIN, TEXAS 78712;