We built climate envelope models under contemporary and future climates to explore potential range shifts of the invasive Red Shiner-Cyprinella lutrensis. Our objective was to estimate aquatic habitat vulnerability to...We built climate envelope models under contemporary and future climates to explore potential range shifts of the invasive Red Shiner-Cyprinella lutrensis. Our objective was to estimate aquatic habitat vulnerability to Red Shiner invasion in North America under future climatic change. We used presence records from within the species’ native and invaded distributions, a suite of bioclimatic predictor variables from three climate models (CCCma, CSIRO, and HadCM3), and maximum entropy modeling to generate potential distribution maps for the year 2080. Our model predicted major range expansion by Red Shiner under both low and high carbon emissions scenarios. The models exceeded average area under the receiver operator characteristic curve values of 0.92, indicating good overall model performance. The model predictions fell largely outside of areas of climatic extrapolation (i.e. regions predicted into environments different from training the region) indicating good model performance. The results from this study highlight the large potential range expansion across North America of Red Shiner under future warmer climates.展开更多
We examined the genetic diversity on a microgeographic scale of Rhinichthys atratulus (Eastern Blacknose Dace) in Allyn Brook, a small tributary in the upper Coginchaug River drainage in Connecticut. By looking at gen...We examined the genetic diversity on a microgeographic scale of Rhinichthys atratulus (Eastern Blacknose Dace) in Allyn Brook, a small tributary in the upper Coginchaug River drainage in Connecticut. By looking at gene flow on a microgeographic scale among populations that had no physical barriers to migration, we tested the null hypothesis that the populations should be homogeneous. We resolved seven polymorphic microsatellite loci and one mitochondrial gene, nd2, in three adjacent populations (<0.5 km) in Allyn Brook and compared these populations to the two closest populations (>5 km) in the Coginchaug River. A dam from the 1920’s in lower Allyn Brook has isolated Allyn-Brook populations from Coginchaug-River populations. Allyn Brook was selected because there are only three riffle habitats in the brook and, therefore, there can be no immigration from upstream populations. Each population has private (i.e., unique) alleles and haplotypes, and there are significant genetic differences between all sites. The Allyn Brook populations are almost as different from one another as they are from the distant populations in the Coginchaug River from which they have been isolated for more than 80 years. These results point to in situ evolution and little migration or gene flow among populations on a microgeographic scale. This raises interesting questions for conservation of genetic diversity of stream fishes.展开更多
文摘We built climate envelope models under contemporary and future climates to explore potential range shifts of the invasive Red Shiner-Cyprinella lutrensis. Our objective was to estimate aquatic habitat vulnerability to Red Shiner invasion in North America under future climatic change. We used presence records from within the species’ native and invaded distributions, a suite of bioclimatic predictor variables from three climate models (CCCma, CSIRO, and HadCM3), and maximum entropy modeling to generate potential distribution maps for the year 2080. Our model predicted major range expansion by Red Shiner under both low and high carbon emissions scenarios. The models exceeded average area under the receiver operator characteristic curve values of 0.92, indicating good overall model performance. The model predictions fell largely outside of areas of climatic extrapolation (i.e. regions predicted into environments different from training the region) indicating good model performance. The results from this study highlight the large potential range expansion across North America of Red Shiner under future warmer climates.
文摘We examined the genetic diversity on a microgeographic scale of Rhinichthys atratulus (Eastern Blacknose Dace) in Allyn Brook, a small tributary in the upper Coginchaug River drainage in Connecticut. By looking at gene flow on a microgeographic scale among populations that had no physical barriers to migration, we tested the null hypothesis that the populations should be homogeneous. We resolved seven polymorphic microsatellite loci and one mitochondrial gene, nd2, in three adjacent populations (<0.5 km) in Allyn Brook and compared these populations to the two closest populations (>5 km) in the Coginchaug River. A dam from the 1920’s in lower Allyn Brook has isolated Allyn-Brook populations from Coginchaug-River populations. Allyn Brook was selected because there are only three riffle habitats in the brook and, therefore, there can be no immigration from upstream populations. Each population has private (i.e., unique) alleles and haplotypes, and there are significant genetic differences between all sites. The Allyn Brook populations are almost as different from one another as they are from the distant populations in the Coginchaug River from which they have been isolated for more than 80 years. These results point to in situ evolution and little migration or gene flow among populations on a microgeographic scale. This raises interesting questions for conservation of genetic diversity of stream fishes.
