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Linking Direct And Indirect Data On Dispersal: Isolation By Slope In A Headwater Stream Salamander, Winsor H. Lowe, Gene E. Likens, Mark A. Mcpeek, Don C. Buso Feb 2006

Linking Direct And Indirect Data On Dispersal: Isolation By Slope In A Headwater Stream Salamander, Winsor H. Lowe, Gene E. Likens, Mark A. Mcpeek, Don C. Buso

Dartmouth Scholarship

There is growing recognition of the need to incorporate information on movement behavior in landscape-scale studies of dispersal. One way to do this is by using indirect indices of dispersal (e.g., genetic differentiation) to test predictions derived from direct data on movement behavior. Mark–recapture studies documented upstream-biased movement in the salamander Gyrinophilus porphyriticus (Plethodontidae). Based on this information, we hypothesized that gene flow in G. porphyriticus is affected by the slope of the stream. Specifically, because the energy required for upstream dispersal is positively related to slope, we predicted gene flow to be negatively related to change in elevation between …


Leptodactylus Fragilis, Mirriiam Muedeking Heyer, W. Ronald Heyer, Rafael O. De Sá Jan 2006

Leptodactylus Fragilis, Mirriiam Muedeking Heyer, W. Ronald Heyer, Rafael O. De Sá

Biology Faculty Publications

Leptodactylus fragilis (Brocchi) White-lipped thin-toed frogs are characteristically defined according to their habitation and age. There is a diagnosis of different species group within Leptodactylus. It is furthermore described from different perspectives and discoveries such as its eggs and karyotype. The distribution of the frog is considered to be prominent occurring form Southernmost Teaxs throughout Mexico and Middle America expanding to Venezuela. The fossil fuel records and literature on Leptodactylus are slighly viewed before studying its nomenclatural history and rarity.


The Amphibian Tree Of Life, Darrel R. Frost, Taran Grant, Julián Faivovich, Raoul H. Bain, Alexander Haas, Célio F.B. Haddad, Rafael O. De Sá Jan 2006

The Amphibian Tree Of Life, Darrel R. Frost, Taran Grant, Julián Faivovich, Raoul H. Bain, Alexander Haas, Célio F.B. Haddad, Rafael O. De Sá

Biology Faculty Publications

The evidentiary basis of the currently accepted classification of living amphibians is discussed and shown not to warrant the degree of authority conferred on it by use and tradition. A new taxonomy of living amphibians is proposed to correct the deficiencies of the old one. This new taxonomy is based on the largest phylogenetic analysis of living Amphibia so far accomplished. We combined the comparative anatomical character evidence of Haas (2003) with DNA sequences from the mitochondrial transcription unit H1 (12S and 16S ribosomal RNA and tRNAValine genes, ø 2,400 bp of mitochondrial sequences) and the nuclear genes histone H3, …


The Scent Of Danger: Tetrodotoxin (Ttx) As An Olfactory Cue Of Predation Risk, Richard Zimmer, Daniel Schar, Ryan Ferrer, Patrick Krug, Lee Kats, William Michel Dec 2005

The Scent Of Danger: Tetrodotoxin (Ttx) As An Olfactory Cue Of Predation Risk, Richard Zimmer, Daniel Schar, Ryan Ferrer, Patrick Krug, Lee Kats, William Michel

Lee Kats

Larvae of the California newt (Taricha torosa) exhibit striking predator- avoidance behavior, escaping to refuges in response to a chemical cue from cannibalistic adults. In laboratory flow-tank experiments, stream water collected near free-ranging adults induced hiding responses in 100% of the larvae tested. Solutions prepared by bathing adults (in field and laboratory) also evoked strong hiding behaviors. Insensitive to adult feeding status (fed or starved), and clearly not an excretory product, the chemical cue was released from adult skin (i.e., in swabs of adult backs, sides, and bellies). Tetrodotoxin (TTX) was found in skin swabs of adults and in bathwater …