Conservation Genetics

, Volume 15, Issue 3, pp 573–591

Pronounced differences in genetic structure despite overall ecological similarity for two Ambystoma salamanders in the same landscape

Authors

    • Department of Environmental ConservationUniversity of Massachusetts
    • U.S. Forest Service, Northern Research StationUniversity of Massachusetts
  • Kevin McGarigal
    • Department of Environmental ConservationUniversity of Massachusetts
  • Michael K. Schwartz
    • U.S. Forest Service, Rocky Mountain Research Station
Research Article

DOI: 10.1007/s10592-014-0562-7

Cite this article as:
Whiteley, A.R., McGarigal, K. & Schwartz, M.K. Conserv Genet (2014) 15: 573. doi:10.1007/s10592-014-0562-7

Abstract

Studies linking genetic structure in amphibian species with ecological characteristics have focused on large differences in dispersal capabilities. Here, we test whether two species with similar dispersal potential but subtle differences in other ecological characteristics also exhibit strong differences in genetic structure in the same landscape. We examined eight microsatellites in marbled salamanders (Ambystoma opacum) from 29 seasonal ponds and spotted salamanders (Ambystoma maculatum) from 19 seasonal ponds in a single geographic region in west-central Massachusetts. Despite overall similarity in ecological characteristics of spotted and marbled salamanders, we observed clear differences in the genetic structure of these two species. For marbled salamanders, we observed strong overall genetic differentiation (F ST = 0.091, F′ ST = 0.375), three population-level clusters of populations (K = 3), a strong pattern of isolation by distance (r = 0.58), and marked variation in family-level structure (from 1 to 23 full-sibling families per site). For spotted salamanders, overall genetic differentiation was weaker (F ST = 0.025, F′ ST = 0.102), there was no evidence of population-level clustering (K = 1), the pattern of isolation by distance (r = 0.17) was much weaker compared to marbled salamanders, and there was less variation in family-level structure (from 10 to 36 full-sibling families per site). We suspect that a combination of breeding site fidelity, effective population size, and generation interval is responsible for these marked differences. Our results suggest that marbled salamanders, compared to spotted salamanders, are more sensitive to fragmentation from various land-use activities and would be less likely to recolonize extirpated sites on an ecologically and conservation-relevant time frame.

Keywords

Genetic structure Full-sibling families Ambystoma Effective number of breeders Life-history

Supplementary material

10592_2014_562_MOESM1_ESM.docx (273 kb)
Supplementary material 1 (DOCX 272 kb)

Copyright information

© Springer Science+Business Media Dordrecht 2014