DOI: 10.5061/dryad.kprr4xh20
title: Spatiotemporal population dynamics of the Caddo Madtom (Noturus taylori), a narrow-range endemic of the Ouachita Highlands

description: The Caddo Madtom, Noturus taylori, is endemic to three river
 drainages of the Ouachita Highlands in the southeastern United States.
 Conservation concern for N. taylori has been heightened
 by recent studies based on analyses of allozyme data suggesting population
 decline and a possible extirpation event, which lead to N.
 taylori petitioned for listing under the Endangered Species Act
 in 2011. The objective of this study was to determine if contemporary
 factors, historic processes, or a combination of both, using
 microsatellite DNA loci and mitochondrial (mt) DNA, have influenced
 patterns of genetic structuring for N. taylori to better
 inform conservation management strategies. Phylogeographic and Bayesian
 cluster analyses suggest that genetic structuring between Caddo and
 Ouachita river drainages was shaped by historical processes prior to
 construction of reservoir dams that dissect the drainages. We found no
 evidence that reservoir dams influenced contemporary patterns of genetic
 structure, thus it is likely that larger river courses, and life-history
 characteristics conducive to headwater habitats, play important roles in
 limiting gene flow between drainages, and to some extent within drainages.
 Genetic diversity of N. taylori was relatively high
 compared to other endangered madtom species; however, compared to the
 Ouachita River population, genetic diversity was significantly lower for
 the Caddo River population. Collectively, these results suggest
 that N. taylori populations are not heavily impaired,
 and the genetic variation and structuring is most attributable to historic
 processes. However, the endemic status and narrowly fragmented
 distribution still renders N. taylori populations
 vulnerable to extirpation or extinction by stochastic events.
description: Tissues samples were collected from up to 30 Caddo Madtom
 individuals per locality throughout the Ouachita River basin in
 southwestern Arkansas. A total of 137 individuals were successfully
 genotyped for 10 microsatellite DNA loci, with primers designed for the
 Slender, Smoky, and Yellowfin madtoms. Up to 10 individuals per
 sub-drainage were additionally amplified for the mitochondrial cytochrome
 <em>b</em> gene (cyt <em>b</em>). The cyt
 <em>b</em> sequences were accessioned with GenBank.
description: Microsatellite data GENEPOP format The
 microsatellite DNA data file is in GENEPOP format. The file includes
 genotype scores for 10 microsatellite loci for the Caddo Madtom. Locus
 names are listed under the title line at the top of the file. POP refers
 to populations described in the manuscript. The populations are ordered as
 follows: (1) Caddo River; (2) tributary to the Caddo River, Lick Creek;
 (3) South Fork Caddo River; (4) Ouachita River; (5) South Fork Ouachita
 River. Each row below POP identifiers represents an individual followed by
 their genotype for the ten loci. Individual identifiers and specimen
 information can be found in the associated excel file named
 "SpecimenInformation_Dryad.xlsx". Allele scores for each locus
 are concatenated into six digits, with the first three numbers
 representing the size of allele "one" and the second three
 numbers representing the size of allele "two". Missing data are
 coded as "000".
 CaddoMadtom_GENEPOP.txt
 SpecimenInformation_Dryad Detailed
 information for Caddom Madtom samples used in this study. Museum tissue
 catalog or specimen voucher catalog numbers are followed by individual
 identifiers and collection locality information. Specimens and/or tissues
 were cataloged in the Arkansas State University Museum of Zoology
 (ASUMZ).