title: Novel Concordance Between Geographic, Environmental, and Genetic Structure in the Ecological Generalist Prickly Sculpin (Cottus asper) in California.
abstract: Ecological generalists may contain a wealth of information concerning diversity, ecology, and geographic connectivity throughout their range. We explored these ideas in prickly sculpin (Cottus asper), a small generalist freshwater fish species where coastal forms have potentially undergone radiations into inland lacustrine and riverine environments. Using a 962bp cytochrome b mtDNA marker and 11 microsatellites, we estimated diversity, divergence times, gene flow, and structure among populations at 43 locations throughout California. We then incorporated genetic and GIS data into ecological niche models to assess ecological conditions within identified groups. Though not reciprocally monophyletic, unique mtDNA haplotypes, microsatellite clustering, and measures of isolation by distance (Coastal: r = 0.960, P < 0.001; Inland: r = 0.277, P = 0.148) suggest 2 novel taxonomic groups, Coastal and Inland (constrained to Great Central Valley). Divergence estimates of 41-191 kya combined with the regional biogeographic history suggest geographic barriers are absent between groups since divergence, but ecological niche modeling revealed significant environmental differences (t = 10.84, P < 0.001). Introgressed individuals were also discovered between groups in an ecologically and geographically intermediate region. Population structure was limited, predominately found in tributaries of the San Joaquin basin in the Inland group. Overall, C. asper exhibited substantial genetic diversity, despite its ecological generality, reflecting California's historically unique and complex hydrology. More broadly, this study illustrates variable environments within the range of a generalist species may mask genetic divergences and should not be overlooked in biodiversity assessments.
authors.affiliation: From the School of Natural Sciences and Sierra Nevada Research Institute, University of California Merced, 5200N. Lake Road, Merced, CA 95344 (Baumsteiger, Aguilar); Department of Fisheries Biology, Humboldt State University, 1 Harpst Street, Arcata, CA 95521 (Kinziger). Baumsteiger is now at the Center for Watershed Sciences, University of California Davis, One Shields Avenue, Davis, CA 95616; and Aguilar is now at Department of Biological Sciences, California State University, Los Angeles, 5151 State University Drive, Los Angeles, CA 90032-8530. jbaumsteiger@ucdavis.edu.
authors.forename: Jason
authors.initials: J
authors.lastname: Baumsteiger
authors.affiliation: From the School of Natural Sciences and Sierra Nevada Research Institute, University of California Merced, 5200N. Lake Road, Merced, CA 95344 (Baumsteiger, Aguilar); Department of Fisheries Biology, Humboldt State University, 1 Harpst Street, Arcata, CA 95521 (Kinziger). Baumsteiger is now at the Center for Watershed Sciences, University of California Davis, One Shields Avenue, Davis, CA 95616; and Aguilar is now at Department of Biological Sciences, California State University, Los Angeles, 5151 State University Drive, Los Angeles, CA 90032-8530.
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Kinziger
authors.affiliation: From the School of Natural Sciences and Sierra Nevada Research Institute, University of California Merced, 5200N. Lake Road, Merced, CA 95344 (Baumsteiger, Aguilar); Department of Fisheries Biology, Humboldt State University, 1 Harpst Street, Arcata, CA 95521 (Kinziger). Baumsteiger is now at the Center for Watershed Sciences, University of California Davis, One Shields Avenue, Davis, CA 95616; and Aguilar is now at Department of Biological Sciences, California State University, Los Angeles, 5151 State University Drive, Los Angeles, CA 90032-8530.
authors.forename: Andres
authors.initials: A
authors.lastname: Aguilar
mesh_terms: D000818:Animals; D002140:California; D004272:DNA, Mitochondrial; D004777:Environment; D019143:Evolution, Molecular; D005399:Fishes / Q000145:classification* / Q000235:genetics*; D014644:Genetic Variation; D005828:Genetics, Population; D006239:Haplotypes; D008386:Marine Biology; D018895:Microsatellite Repeats; D010802:Phylogeny; D058974:Phylogeography
chemical_list: D004272:DNA, Mitochondrial
keywords: ecological niche models; inland radiation; microsatellites; phylogeography