Conservation Genetics of an Imperiled Riverine Fish from Eastern North America, the Blotchside Logperch, Percina Burtoni (Teleostei: Percidae)
Percina burtoni (Percidae: subgenus Percina), Blotchside Logperch, historically occupied much of the Tennessee and Cumberland River drainages, but is now restricted to highly fragmented populations where they occur at low densities. Widespread impoundment and subsequent river alteration over the past 60 years has eliminated many populations and reduced the potential for dispersal and gene flow between extant populations. We examined genetic variation at two mitochondrial genes, cytochrome b and ND2, from 74 individuals in ten populations to assess genetic population structure within P. burtoni. These data, as well as the results of recent surveys, were used to assess conservation priorities for this imperiled fish. Phylogenetic analysis recovered two well supported and highly differentiated clades within P. burtoni, one containing individuals from the Duck River drainage and a small tributary to the lower Tennessee River, and the other composed of individuals from the middle and upper Tennessee River drainage. The Duck River clade exhibits lower haplotypic and nucleotide diversity than the Tennessee River clade and shows little geographic partitioning. In contrast, most populations of middle and upper Tennessee River P. burtoni possess unique haplotypes and show strong geographic differentiation. Historical isolation of small populations in tributary systems of the upper Tennessee Basin is hypothesized to be responsible for observed patterns of differentiation within this clade. These results have implications for reintroduction programs and population augmentation with captive-reared individuals. Propagation activities should take fine-scale geographic structure into account prior to any reintroduction activities.Abstract
Distribution of Percina burtoni in the Tennessee and Cumberland river drainages.
Open circles represent extirpated populations with date of last collection, closed circles represent localities from which we collected individuals, and grey circles are currently extant localities where we were unable to collect P. burtoni. The open circle with an open star represents the type locality for P. burtoni in the Swannanoa River, Asheville, NC, which is now presumed extirpated. Abbreviations for collection sites follow Table 1, and are as follows: WO: Whiteoak Creek; DU: Duck River; BU: Buffalo River; SH: Shoal Creek; PR: Paint Rock River; SC: Spring Creek; LR: Little River; NH: N. Fk. Holston River; CC: Copper Creek; CR: Clinch River.
Sample phylogram from 1000 trees produced by Bayesian analysis.
Stars represent nodes with over 0.95 posterior probability. Localities correspond to those listed in Table 1.
Haplotype network for P. burtoni (above) and P. sp. cf. burtoni (below) representing 20 haplotypes with 74 individuals.
Circle size reflects the frequency of haplotypes, solid lines connecting haplotypes represent one mutational event, and small black circles represent missing or theoretical haplotypes. Abbreviations are as listed in Table 1. Numbers listed after each abbreviation indicate how many individuals were recovered with this haplotype; circles with no numbers indicate only one individual was found with this haplotype.
Contributor Notes
DEPARTMENT OF BIOLOGY, SAINT LOUIS UNIVERSITY, 3507 LACLEDE AVENUE, ST. LOUIS, MISSOURI 63103.