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Full-Text Articles in Physical Sciences and Mathematics

Speciation With Gene Flow In A Narrow Endemic West Virginia Cave Salamander (Gyrinophilus Subterraneus), Evan H. Campbell Grant, Kevin P. Mulder, Adrianne B. Brand, Douglas B. Chambers, Addison H. Wynn, Grace Capshaw, Matthew L. Niemiller, John G. Phillips, Jeremy F. Jacobs, Shawn R. Kuchta, Rayna C. Bell Jun 2022

Speciation With Gene Flow In A Narrow Endemic West Virginia Cave Salamander (Gyrinophilus Subterraneus), Evan H. Campbell Grant, Kevin P. Mulder, Adrianne B. Brand, Douglas B. Chambers, Addison H. Wynn, Grace Capshaw, Matthew L. Niemiller, John G. Phillips, Jeremy F. Jacobs, Shawn R. Kuchta, Rayna C. Bell

United States Geological Survey: Staff Publications

Due to their limited geographic distributions and specialized ecologies, cave species are often highly endemic and can be especially vulnerable to habitat degradation within and surrounding the cave systems they inhabit. We investigated the evolutionary history of the West Virginia Spring Salamander (Gyrinophilus subterraneus), estimated the population trend from historic and current survey data, and assessed the current potential for water quality threats to the cave habitat. Our genomic data (mtDNA sequence and ddRADseq-derived SNPs) reveal two, distinct evolutionary lineages within General Davis Cave corresponding to G. subterraneus and its widely distributed sister species, Gyrinophilus porphyriticus, that …


Distribution And Environmental Limitations Of An Amphibian Pathogen In The Rocky Mountains, Usa, Erin Muths, David S. Pilliod, Lauren J. Livo Jan 2008

Distribution And Environmental Limitations Of An Amphibian Pathogen In The Rocky Mountains, Usa, Erin Muths, David S. Pilliod, Lauren J. Livo

United States Geological Survey: Staff Publications

Amphibian populations continue to be imperiled by the chytrid fungus (Batrachochytrium dendrobatidis). Understanding where B. dendrobatidis (Bd) occurs and how it may be limited by environmental factors is critical to our ability to effectively conserve the amphibians affected by Bd. We sampled 1247 amphibians (boreal toads and surrogates) at 261 boreal toad (Bufo boreas) breeding sites (97 clusters) along an 11° latitudinal gradient in the Rocky Mountains to determine the distribution of B. dendrobatidis and examine environmental factors, such as temperature and elevation, that might affect its distribution. The fungus was detected at …


Saprolegniaceae Identified On Amphibian Eggs Throughout The Pacific Northwest, Usa, By Internal Transcribed Spacer Sequences And Phylogenetic Analysis, Jill E. Petrisko, Christopher A. Pearl, David S. Pilliod, Peter P. Sheridan, Charles F. Williams, Charles R. Peterson, R. Bruce Bury Nov 2007

Saprolegniaceae Identified On Amphibian Eggs Throughout The Pacific Northwest, Usa, By Internal Transcribed Spacer Sequences And Phylogenetic Analysis, Jill E. Petrisko, Christopher A. Pearl, David S. Pilliod, Peter P. Sheridan, Charles F. Williams, Charles R. Peterson, R. Bruce Bury

United States Geological Survey: Staff Publications

We assessed the diversity and phylogeny of Saprolegniaceae on amphibian eggs from the Pacific Northwest, with particular focus on Saprolegnia ferax, a species implicated in high egg mortality. We identified isolates from eggs of six amphibians with the internal transcribed spacer (ITS) and 5.8S gene regions and BLAST of the GenBank database. We identified 68 sequences as Saprolegniaceae and 43 sequences as true fungi from at least nine genera. Our phylogenetic analysis of the Saprolegniaceae included isolates within the genera Saprolegnia, Achlya and Leptolegnia. Our phylogeny grouped S. semihypogyna with Achlya rather than with the Saprolegnia reference …


Distribution Patterns Of Lentic-Breeding Amphibians In Relation To Ultraviolet Radiation Exposure In Western North America, Michael J. Adams, Blake R. Hossack, Roland A. Knapp, Paul Stephen Corn, Stephen A. Diamond, Peter C. Trenham, Dan B. Fagre Jul 2005

Distribution Patterns Of Lentic-Breeding Amphibians In Relation To Ultraviolet Radiation Exposure In Western North America, Michael J. Adams, Blake R. Hossack, Roland A. Knapp, Paul Stephen Corn, Stephen A. Diamond, Peter C. Trenham, Dan B. Fagre

United States Geological Survey: Staff Publications

An increase in ultraviolet-B (UV-B) radiation has been posited to be a potential factor in the decline of some amphibian population. This hypothesis has received support from laboratory and field experiments showing that current levels of UV-B can cause embryo mortality in some species, but little research has addressed whether UV-B is influencing the distribution of amphibian populations. We compared patterns of amphibian presence to sitespecific estimates of UV-B dose at 683 ponds and lakes in Glacier, Olympic, and Sequoia–Kings Canyon National Parks. All three parks are located in western North America, a region with a concentration of documented amphibian …


Amphibian Research And Monitoring Initiative (Armi): A Successful Start To A National Program In The United States, Erin Muths, Robin E. Jung, Larissa L. Bailey, Michael J. Adams, P. Stephen Corn, C. Kenneth Dodd Jr., Gary M. Fellers, Walter J. Sadinski, Cecil R. Schwalbe, Susan C. Walls, Robert N. Fisher, Alisa L. Gallant, William A. Battaglin, D. Earl Green Jan 2005

Amphibian Research And Monitoring Initiative (Armi): A Successful Start To A National Program In The United States, Erin Muths, Robin E. Jung, Larissa L. Bailey, Michael J. Adams, P. Stephen Corn, C. Kenneth Dodd Jr., Gary M. Fellers, Walter J. Sadinski, Cecil R. Schwalbe, Susan C. Walls, Robert N. Fisher, Alisa L. Gallant, William A. Battaglin, D. Earl Green

United States Geological Survey: Staff Publications

Most research to assess amphibian declines has focused on local-scale projects on one or a few species. The Amphibian Research and Monitoring Initiative (ARMI) is a national program in the United States mandated by congressional directive and implemented by the U.S. Department of the Interior (specifically the U.S. Geological Survey, USGS). Program goals are to monitor changes in populations of amphibians across U.S. Department of the Interior lands and to address research questions related to amphibian declines using a hierarchical framework of base-, mid- and apex-level monitoring sites. ARMI is currently monitoring 83 amphibian species (29% of species in the …


Climate Change And Amphibians, P.S. Corn Jan 2005

Climate Change And Amphibians, P.S. Corn

United States Geological Survey: Staff Publications

Amphibian life histories are exceedingly sensitive to temperature and precipitation, and there is good evidence that recent climate change has already resulted in a shift to breeding earlier in the year for some species. There are also suggestions that the recent increase in the occurrence of El Niño events has caused declines of anurans in Central America and is linked to elevated mortality of amphibian embryos in the northwestern United States. However, evidence linking amphibian declines in Central America to climate relies solely on correlations, and the mechanisms underlying the declines are not understood. Connections between embryo mortality and declines …


Evidence For Disease-Related Amphibian Decline In Colorado, Erin Muths, Paul Stephen Corn, Allan P. Pessier, D. Earl Green Jan 2003

Evidence For Disease-Related Amphibian Decline In Colorado, Erin Muths, Paul Stephen Corn, Allan P. Pessier, D. Earl Green

United States Geological Survey: Staff Publications

The recent discovery of a pathogenic fungus (Batrachochytrium dendrobatidis) associated with declines of frogs in the American and Australian tropics, suggests that at least the proximate cause, may be known for many previously unexplained amphibian declines. We have monitored boreal toads in Colorado since 1991 at four sites using capture–recapture of adults and counts of egg masses to examine the dynamics of this metapopulation. Numbers of male toads declined in 1996 and 1999 with annual survival rate averaging 78% from 1991 to 1994, 45% in 1995 and 3% between 1998 and 1999. Numbers of egg masses also declined. …