Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 8 of 8
Full-Text Articles in Life Sciences
The Larvae Of Eurycea Junaluska (Amphibia: Caudata: Plethodontidae), With Comments On Distribution, Travis Ryan
The Larvae Of Eurycea Junaluska (Amphibia: Caudata: Plethodontidae), With Comments On Distribution, Travis Ryan
Travis J. Ryan
Travis J. Ryan's shorter contribution to Copeia 1997.
Does Sex Influence Post-Reproductive Metamorphosis In Ambystoma Talpoideum?, Travis Ryan, Gabrielle Swenson
Does Sex Influence Post-Reproductive Metamorphosis In Ambystoma Talpoideum?, Travis Ryan, Gabrielle Swenson
Travis J. Ryan
Shorter communication in the Journal of Herpetology v. 35.
Growth And The Expression Of Alternative Life Cycles In The Salamander Ambystoma Talpoideum (Caudata: Ambystomatidae), Travis Ryan, Raymond Semlitsch
Growth And The Expression Of Alternative Life Cycles In The Salamander Ambystoma Talpoideum (Caudata: Ambystomatidae), Travis Ryan, Raymond Semlitsch
Travis J. Ryan
Complex life cycles (CLCs) contain larval and adult phases that are morphologically and ecologically distinct. Simple life cycles (SLCs) have evolved from CLCs repeatedly in a wide variety of lineages but the processes that may underlie the transition have rarely been identified or investigated experimentally. We examined the influence of larval growth rate on the facultative expression of alternative life cycles (metamorphosis or maturation as gill-bearing adults [= paedomorphosis]) in the salamander Ambystoma talpoideum. We manipulated growth rates by altering the amount of food individuals received throughout larval development. The expression of alternative life cycles in A. talpoideum is influenced …
Evaporative Water Loss In Two Natricine Snakes, Nerodia Fasciata And Seminatrix Pygaea, Christopher Winne, Travis Ryan, Yale Leiden, Michael Dorcas
Evaporative Water Loss In Two Natricine Snakes, Nerodia Fasciata And Seminatrix Pygaea, Christopher Winne, Travis Ryan, Yale Leiden, Michael Dorcas
Travis J. Ryan
Shorter communication in Journal of Herpetology v. 35.
Aspects Of Sex-Specific Differences In The Expression Of An Alternative Life Cycle In The Salamander Ambystoma Talpoideum, Christopher Winne, Travis Ryan
Aspects Of Sex-Specific Differences In The Expression Of An Alternative Life Cycle In The Salamander Ambystoma Talpoideum, Christopher Winne, Travis Ryan
Travis J. Ryan
A recent evolutionary ecological model of facultative paedomorphosis predicts that body size of mature individuals should be larger than immatures of the same cohort. We investigated sex-specific differences in body size and maturation within a single cohort of branchiate (= larval and paedomorphic) mole salamanders, Ambystoma talpoideum. In addition, we also sampled the population after the breeding season, as some individuals began to undergo metamorphosis and leave the pond. The branchiate population was female-biased (62.7%), and mature (paedomorphic) females were significantly smaller than paedomorphic males or immature (larval) females. The majority of male branchiates were mature (86.6%), whereas significantly fewer …
Life History Evolution And Adaptive Radiation Of Hemidactyliine Salamanders, Travis Ryan, R. Bruce
Life History Evolution And Adaptive Radiation Of Hemidactyliine Salamanders, Travis Ryan, R. Bruce
Travis J. Ryan
T.J. Ryan and R.C. Bruce's contribution to: The Biology of Plethodontid Salamanders, R. C. Bruce, R. G. Jaeger, and L. D. Houck, eds. Kluwer Academic/Plenum Publishers, New York.
Sex And Size Interaction And Standard Metabolic Rate Of Paedomorphic Ambystoma Talpoideum: Size Does Matter, Travis Ryan, William Hopkins
Sex And Size Interaction And Standard Metabolic Rate Of Paedomorphic Ambystoma Talpoideum: Size Does Matter, Travis Ryan, William Hopkins
Travis J. Ryan
We measured the standard metabolic rate of paedomorphic Mole Salamanders (Ambystoma talpoideum) from South Carolina. Despite an absence of body size differences between females and males, analysis of covariance demonstrated metabolic rates (mL O2/h) were significantly influenced by an interaction between sex and body size. The interaction appeared as a result of changes in the size-metabolism relationship in males (a steeper slope in the size-metabolism regression in small males as compared to large males), whereas the relationship remained constant in females, regardless of size. We hypothesize that the observed differences are attributable to differences in reproductive physiology between the sexes. …
Larval Life History And Abundance Of A Rare Salamander, Eurycea Junaluska (Plethodontidae), Travis Ryan
Larval Life History And Abundance Of A Rare Salamander, Eurycea Junaluska (Plethodontidae), Travis Ryan
Travis J. Ryan
The larval life history of Eurycea junaluska was studied in three southwestern North Carolina populations. Populations were sampled quarterly over a 13 mo period and size-class analyses were used to evaluate the pattern of larval growth and metamorphosis. Young of the year appeared in the late spring and experienced rapid growth through the first summer. Growth slowed in the second year and metamorphosis usually occured in the summer at about 25.5 mo post-hatching, although some data suggest that either 1yr or 3yr larval periods may be possible. The overall larval growth rate of E. junaluska is estimated at 1.27 mm/mo, …