Species traits influence the genetic consequences of river fragmentation on two co-occurring redhorse (Moxostoma) species

• Published in: Canadian journal of fisheries and aquatic sciences Vol. 65; no. 9; pp. 1892 - 1904
• Main Authors: Reid, Scott M, Wilson, Chris C, Carl, Leon M, Zorn, Troy G
• Format: Journal Article
• Language: English
• Published: Ottawa, ON National Research Council of Canada 01.09.2008; NRC Research Press; Canadian Science Publishing NRC Research Press
• Subjects: Animal and plant ecology; Animal populations; Animal, plant and microbial ecology; Applied ecology; Biological and medical sciences; Biological diversity; Deoxyribonucleic acid; DNA; Evaluation; Exploitation and management of natural biological resources (hunting, fishing and exploited populations survey, etc.); Fish; Fish populations; Fishes, Fresh-water; Fresh water ecosystems; Freshwater; Fundamental and applied biological sciences. Psychology; Genetic diversity; Genetics; Habitat destruction; Moxostoma carinatum; Moxostoma macrolepidotum; Observations; Rivers; Synecology; Canada; United States; North America; Ontario; America; Michigan; Ontario Canada; Canada, Ontario; Canada, Ontario, Trent R; Bottleneck; Metapopulation; Genetic diversity; Marker; Permeability; Population genetics; Relatedness; Fragmentation; Vertebrata; Recolonization; Pisces; DNA; Stream; Population dynamics; Differentiation
• ISSN: 0706-652X; 1205-7533
• DOI: 10.1139/F08-093

We used microsatellite DNA markers to test whether fragmentation of the Trent River (Ontario, Canada) has reduced genetic diversity and increased genetic differentiation among populations of river redhorse ( Moxostoma carinatum ) and shorthead redhorse (Moxostoma macrolepidotum). Allelic richness of both species was significantly greater along the free-flowing Muskegon River (Michigan, USA) than along the fragmented Trent River. Contrary to expectations, there was no evidence of a fragment length effect on genetic diversity, recent population bottlenecks, or increased relatedness among individuals in fragmented populations. High levels of linkage disequilibrium indicate extinction-recolonization population dynamics along the Trent River. For both species, pairwise F ST tests identified weak but statistically significant population differentiation. In the Trent River, differentiation was significantly greater for river redhorse than for shorthead redhorse and, for both species, greater than in the Muskegon River. Moderate fragmentation effects likely reflect the permeability of the dam-lock system to redhorse movement. Differences between species indicate that as a result of smaller effective population sizes, habitat specialists and species at the periphery of their geographic range are more sensitive to river fragmentation.