| explaining long-distance dispersal: effects of dispersal distance on survival and growth in a stream salamander. | long-distance dispersal (ldd) may contribute disproportionately to range expansions, the creation of new evolutionary lineages, and species persistence in human-dominated landscapes. however, because data on the individual consequences of dispersal distance are extremely limited, we have little insight on how ldd is maintained in natural populations. i used six years of spatially explicit capture-mark-recapture (cmr) data to test the prediction that individual performance increases with dispersa ... | 2010 | 21058560 |
| morphological variation of hypaxial musculature in salamanders (lissamphibia: caudata). | despite the acknowledged importance of the locomotory and respiratory functions associated with hypaxial musculature in salamanders, variation in gross morphology of this musculature has not been documented or evaluated within a phylogenetic or ecological context. in this study, we characterize and quantify the morphological variation of lateral hypaxial muscles using phylogenetically and ecologically diverse salamander species from eight families: ambystomatidae (ambystoma tigrinum), amphiumida ... | 1999 | 10420161 |
| variable infection of stream salamanders in the southern appalachians by the trematode metagonimoides oregonensis (family: heterophyidae). | many factors contribute to parasites varying in host specificity and distribution among potential hosts. metagonimoides oregonensis is a digenetic trematode that uses stream-dwelling plethodontid salamanders as second intermediate hosts in the eastern us. we completed a field survey to identify which stream salamander species, at a regional level, are most likely to be important for transmission to raccoon definitive hosts. we surveyed six plethodontid species (n = 289 salamanders) from 23 appal ... | 2015 | 26026670 |
| acute toxicity of acidity in larvae and adults of four stream salamander species (plethodontidae). | high levels of acid deposition have severely affected streamwater chemistry in the southern appalachians. plethodontid stream salamanders living in and around headwater streams rely on cutaneous respiration and are highly susceptible to changes in water quality. we examined the sensitivity to low ph conditions in four stream salamanders by monitoring the response to six ph treatments ranging from ph 2.75 to 6.5. to quantify acid tolerance, we determined median lethal concentrations (lc50) in 96- ... | 2008 | 18522477 |
| endoparasites of plethodontid salamanders from paradise brook, new hampshire. | totals of 52 dusky salamanders desmognathus fuscus, 51 two-lined salamanders eurycea bislineata, 54 red-backed salamanders plethodon cinereus, and 3 spring salamanders gyrinophilus porphyriticus (plethodontidae) collected in june and august 1995 from paradise brook, a tributary to hubbard brook, new hampshire, were examined for parasites. parasites found were brachycoelium storeriae, brachycoelium sp., bothriocephalus rarus, falcaustra sp., omeia sp., batracholandros magnavulvaris, and cepediett ... | 1997 | 9406804 |
| decoupling of genetic and phenotypic divergence in a headwater landscape. | in stream organisms, the landscape affecting intraspecific genetic and phenotypic divergence is comprised of two fundamental components: the stream network and terrestrial matrix. these components are known to differentially influence genetic structure in stream species, but to our knowledge, no study has compared their effects on genetic and phenotypic divergence. we examined how the stream network and terrestrial matrix affect genetic and phenotypic divergence in two stream salamanders, gyrino ... | 2012 | 22486884 |
| linking movement behaviour to dispersal and divergence in plethodontid salamanders. | to better understand the evolutionary and ecological effects of dispersal, there is growing emphasis on the need to integrate direct data on movement behaviour into landscape-scale analyses. however, little is known about the general link between movement behaviour and large-scale patterns of dispersal and gene flow. likewise, although recent studies suggest that nonrandom, directionally biased movement and dispersal can promote evolutionary divergence, the generality of this mechanism is unknow ... | 2008 | 18803591 |
| biogeography, phylogeny, and morphological evolution of central texas cave and spring salamanders. | subterranean faunal radiations can result in complex patterns of morphological divergence involving both convergent or parallel phenotypic evolution and cryptic species diversity. salamanders of the genus eurycea in central texas provide a particularly challenging example with respect to phylogeny reconstruction, biogeography and taxonomy. these predominantly aquatic species inhabit karst limestone aquifers and spring outflows, and exhibit a wide range of morphological and genetic variation. we ... | 2013 | 24044519 |
| what drives long-distance dispersal? a test of theoretical predictions. | long-distance dispersal (ldd) may contribute disproportionately to species persistence in fragmented landscapes, non-native invasions, and range shifts in response to climate change. however, direct data on ldd are extremely limited, leaving us with little understanding of why it occurs. i used six years of mark-recapture data on the stream salamander gyrinophilus porphyriticus to test theoretical predictions of how variation in habitat quality affects ldd. frequency of ldd was quantified using ... | 2009 | 19569359 |
| impact of cannibalism on predator-prey dynamics: size-structured interactions and apparent mutualism. | direct and indirect interactions between two prey species can strongly alter the dynamics of predator-prey systems. most predators are cannibalistic, and as a consequence, even systems with only one predator and one prey include two prey types: conspecifics and heterospecifics. the effects of the complex direct and indirect interactions that emerge in such cannibalistic systems are still poorly understood. this study examined how the indirect interaction between conspecific and heterospecific pr ... | 2008 | 18589529 |
| speciation with gene flow could be common. | the likelihood of speciation in the face of homogenizing gene flow (i.e. without complete geographical isolation) is one of the most debated topics in evolutionary biology. demonstrating this phenonemon is hampered by the difficulty of isolating the effects of time since population divergence vs. gene flow on levels of molecular genetic differentiation. for example, weak genetic differentiation between taxa could be due to recent divergence, gene flow, or a combination of these factors. nonethel ... | 2008 | 18410295 |
| recent divergence with gene flow in tennessee cave salamanders (plethodontidae: gyrinophilus) inferred from gene genealogies. | cave organisms occupy a special place in evolutionary biology because convergent morphologies of many species demonstrate repeatability in evolution even as they obscure phylogenetic relationships. the origin of specialized cave-dwelling species also raises the issue of the relative importance of isolation vs. natural selection in speciation. two alternative hypotheses describe the origin of subterranean species. the 'climate-relict' model proposes allopatric speciation after populations of cold ... | 2008 | 18410292 |
| the influence of size-specific indirect interactions in predator-prey systems. | nonlethal indirect interactions between predators often lead to nonadditive effects of predator number on prey survival and growth. previous studies have focused on systems with at least two different predator species and one prey species. however, most predators undergo extreme ontological changes in phenotype such that interactions between different-sized cohorts of a predator and its prey could lead to nonadditive effects in systems with only two species. this may be important since different ... | 2006 | 16637362 |
| linking direct and indirect data on dispersal: isolation by slope in a headwater stream salamander. | 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 affecte ... | 2006 | 16637359 |
| intraguild predation among larval plethodontid salamanders: a field experiment in artificial stream pools. | intraguild predation can be important in determining community structure and dynamics. artificial stream pools were used to test for the impacts of intraguild predation among three species of larval plethodontid salamanders. intraguild predators (large gyrinophilus porphyriticus and pseudotriton ruber) significantly decreased the survival of small pseudotriton ruber. there was a trend toward reduced growth of pseudotriton and eurycea cirrigera in the presence of intraguild predators. the presenc ... | 1993 | 28313424 |
| skeletal morphogenesis in the urodele skull: ii. effect of developmental stage in thyroid hormone-induced remodeling. | this study investigates the effect of developmental stage on thyroid hormone (th)-mediated remodeling in the skeletal tissues of hemidactyliine plethodontid urodeles. rate of morphogenesis was quantified in 17 metamorphic tissues for three different size-age classes of eurycea bislineata larvae immersed in a metamorphic dosage of t4 . extent of morphogenesis after a 3-week immersion was also quantified in these tissues plus four larval ones for the full size range of e. bislineata larvae and for ... | 1995 | 29865295 |
| skeletal morphogenesis in the urodele skull: i. postembryonic development in the hemidactyliini (amphibia: plethodontidae). | the metamorphic species eurycea bislineata is presented as a standard for evaluating the relationship between cranial ontogeny and life history in hemidactyliine plethodontid urodeles. past and present descriptions are combined into a comprehensive summary of postembryonic skull development for this species, and the sequence, sizes of onset, and morphogenetic pathways are documented for all major remodelling events. developmental series are also compared intraspecifically, between two population ... | 1995 | 29865294 |
| long-term survival probability, not current habitat quality, predicts dispersal distance in a stream salamander. | dispersal evolves as an adaptive mechanism to optimize individual fitness across the landscape. specifically, dispersal represents a mechanism to escape fitness costs resulting from changes in environmental conditions. decades of empirical work suggest that individuals use local habitat cues to make movement decisions, but theory predicts that dispersal can also evolve as a fixed trait, independent of local conditions, in environments characterized by a history of stochastic spatiotemporal varia ... | 2020 | 31958140 |
| a distance-performance trade-off in the phenotypic basis of dispersal. | across taxa, individuals vary in how far they disperse, with most individuals staying close to their origin and fewer dispersing long distances. costs associated with dispersal (e.g., energy, risk) are widely believed to trade off with benefits (e.g., reduced competition, increased reproductive success) to influence dispersal propensity. however, this framework has not been applied to understand variation in dispersal distance, which is instead generally attributed to extrinsic environmental fac ... | 2019 | 31624572 |
| hydrologic variability contributes to reduced survival through metamorphosis in a stream salamander. | changes in the amount, intensity, and timing of precipitation are increasing hydrologic variability in many regions, but we have little understanding of how these changes are affecting freshwater species. stream-breeding amphibians-a diverse group in north america-may be particularly sensitive to hydrologic variability during aquatic larval and metamorphic stages. here, we tested the prediction that hydrologic variability in streams decreases survival through metamorphosis in the salamander gyri ... | 2019 | 31488710 |
| matching habitat choice and plasticity contribute to phenotype-environment covariation in a stream salamander. | populations optimize the match of phenotype to environment by localized natural selection, adaptive phenotypic plasticity, and habitat choice. habitat choice may also be achieved by several mechanisms, including matching habitat choice, where individuals distribute themselves based on self-assessment of the phenotype-environment match. matching habitat choice is a relatively untested concept, but one that could advance our understanding of the interplay of movement ecology and intraspecific phen ... | 2019 | 30770554 |