| coalescent-based hypothesis testing supports multiple pleistocene refugia in the pacific northwest for the pacific giant salamander (dicamptodon tenebrosus). | phylogeographic patterns of many taxa are explained by pleistocene glaciation. the temperate rainforests within the pacific northwest of north america provide an excellent example of this phenomenon, and competing phylogenetic hypotheses exist regarding the number of pleistocene refugia influencing genetic variation of endemic organisms. one such endemic is the pacific giant salamander, dicamptodon tenebrosus. in this study, we estimate this species' phylogeny and use a coalescent modeling appro ... | 2006 | 16842421 |
| structure and evolution of supernumerary chromosomes in the pacific giant salamander, dicamptodon tenebrosus. | we examined the genetic make-up and plausible origins of the supernumerary (b) chromosomes of the pacific giant salamander, dicamptodon tenebrosus, from the pacific northwest of north america. these salamanders have variable numbers of b chromosomes, from 0 to 10 per individual. salamanders from the most southerly and northerly regions of the species' range have lower average numbers of b chromosomes than salamanders in the middle of the range. to assess how the supernumerary chromosomes origina ... | 2000 | 11032318 |
| structure and evolution of b chromosomes in amphibians. | b chromosomes are known from 26 species of salamanders and frogs, equivalent to about 2% of amphibian species that have been karyotyped. in most cases, the structure of amphibian b chromosomes has not been extensively investigated. the exceptions are the b chromosomes of hochstetter's frog, leiopelma hochstetteri, from new zealand, and the coastal giant salamander, dicamptodon tenebrosus, from north america. dicamptodon tenebrosus carries from 0 to 10 non-heterochromatic, telocentric b chromosom ... | 2004 | 15292597 |
| current and historical drivers of landscape genetic structure differ in core and peripheral salamander populations. | with predicted decreases in genetic diversity and greater genetic differentiation at range peripheries relative to their cores, it can be difficult to distinguish between the roles of current disturbance versus historic processes in shaping contemporary genetic patterns. to address this problem, we test for differences in historic demography and landscape genetic structure of coastal giant salamanders (dicamptodon tenebrosus) in two core regions (washington state, united states) versus the speci ... | 2012 | 22590604 |
| predator-driven nutrient recycling in california stream ecosystems. | nutrient recycling by consumers in streams can influence ecosystem nutrient availability and the assemblage and growth of photoautotrophs. stream fishes can play a large role in nutrient recycling, but contributions by other vertebrates to overall recycling rates remain poorly studied. in tributaries of the pacific northwest, coastal giant salamanders (dicamptodon tenebrosus) occur at high densities alongside steelhead trout (oncorhynchus mykiss) and are top aquatic predators. we surveyed the de ... | 2013 | 23520520 |
| hindlimb kinematics during terrestrial locomotion in a salamander (dicamptodon tenebrosus) | a quantitative study of hindlimb kinematics during terrestrial locomotion in a non-specialized salamander was undertaken to allow comparisons with limb movements in other groups of tetrapods. five dicamptodon tenebrosus were videotaped at 200 fields s-1 walking on a treadmill. coordinates of marker points on the salamander's midline, pelvic girdle and left hindlimb were digitized through at least three strides at both a walk (0.77 svl s-1, where svl is snout­vent length) and a trot (2.90 svl ... | 1994 | 9317755 |
| metamorphic and speed effects on hindlimb kinematics during terrestrial locomotion in the salamander dicamptodon tenebrosus | the kinematics of the hindlimb during terrestrial treadmill locomotion in dicamptodon tenebrosus were compared between larval and metamorphosed individuals at different speeds. coordinates of marker points on the salamander's midline, pelvic girdle and left hindlimb were digitized from high-speed videos (200 fields s-1). these yielded kinematic variables describing trunk flexion, pelvic girdle rotation, femoral protraction/retraction and knee flexion/extension. a three-way analysis of variance t ... | 1994 | 9317817 |
| motor patterns and kinematics during backward walking in the pacific giant salamander: evidence for novel motor output. | kinematic and motor patterns during forward and backward walking in the salamander dicamptodon tenebrosus were compared to determine whether the differences seen in mammals also apply to a lower vertebrate with sprawling posture and to measure the flexibility of motor output by tetrapod central pattern generators. during treadmill locomotion, electromyograms (emgs) were recorded from hindlimb muscles of dicamptodon while simultaneous high-speed video records documented movement of the body, thig ... | 1997 | 9405524 |
| olfactory metamorphosis in the coastal giant salamander (dicamptodon tenebrosus). | this study examined the gross morphology and ultrastructure of the olfactory organ of larvae, neotenic adults, and terrestrial adults of the coastal giant salamander (dicamptodon tenebrosus). the olfactory organ of all aquatic animals (larvae and neotenes) is similar in structure, forming a tube extending from the external naris to the choana. a nonsensory vestibule leads into the main olfactory cavity. the epithelium of the main olfactory cavity is thrown into a series of transverse valleys and ... | 2005 | 16121394 |
| polymorphic tetranucleotide microsatellites for cope's giant salamander (dicamptodon copei) and pacific giant salamander (dicamptodon tenebrosus). | we present primers and amplification conditions for 15 microsatellite loci developed for the cope's giant salamander (dicamptodon copei), 14 of which are tetranucleotide repeats. cross-species amplification revealed 10 of these loci to also be polymorphic in the pacific giant salamander (dicamptodon tenebrosus). several loci produced nonoverlapping allelic ranges between the two species and may be useful in species identification. these polymorphic microsatellite loci are potentially useful for ... | 2008 | 21585975 |
| new microsatellite markers for examining genetic variation in peripheral and core populations of the coastal giant salamander (dicamptodon tenebrosus). | the coastal giant salamander (dicamptodon tenebrosus) is classified as threatened at the northern periphery of its range in british columbia (bc), canada, primarily due to forestry practices and habitat fragmentation. characterising dispersal behaviour and population connectivity is therefore a priority for this region, while genetic differentiation in core versus peripheral locations remains unstudied in this wide-ranging species. we present seven new polymorphic microsatellite markers for use ... | 2010 | 21179519 |
| the comparative myology of the thigh and crus in the salamanders ambystoma tigrinum and dicamptodon tenebrosus. | variation in myology of the hind limb among salamanders has been poorly characterized. nineteen major hind limb muscles of ambystoma tigrinum (ambystomatidae) and dicamptodon tenebrosus (dicamptodontidae) were studied to provide baseline descriptive data on hind limb myology in salamanders and to generate hypotheses of hind limb muscle function. most superficial muscles of the hind limbs span multiple joints, including a unique three-joint muscle, the ischioflexorius, that extends from the pelvi ... | 1992 | 29865579 |
| isolation and characterization of microsatellite loci in the pacific giant salamander dicamptodon tenebrosus. | | 2000 | 10652085 |