Document Type

Article

Publication Date

2009

Publication Title

Conservation Genetics

Volume

10

First Page

477

Last Page

487

DOI

10.1007/s10592-008-9627-9

Keywords

Temporal stability, Microsatellites, Greenside Darter, Genetic structure, Dispersal, Barriers, Species range

Abstract

The genetic structure of a stream-dwelling fish, the Greenside Darter, Etheostoma blennioides, is described from variation at nine microsatellite loci in 26 populations in the northern-most portions of the species’ range in southern Ontario, Canada in two sampling years. We found relatively high levels of genetic structure at the among- and within-watershed scales, with some watersheds and populations exhibiting very high divergence. The Ausable River populations were especially isolated, containing distinct populations of potential conservation concern. Temporal replicates at selected localities showed evidence of substantial temporal variation in genetic structure, perhaps resulting from movement among sites. We found strong evidence for an effect of river barriers (dams and weirs) on dispersal measured by genotype assignment techniques. However, we found no bias in upstream vs downstream dispersal. Significant isolation-by-distance relationships in both sample years indicate that river distance is an important factor regulating gene flow in these watersheds. The Canadian Greenside Darter populations are expanding their range into more northerly watersheds, but also show substantial within-watershed genetic structure despite substantial dispersal.

Available for download on Sunday, January 01, 2119

Share

COinS