Torrent salamander
| Torrent salamanders | |
|---|---|
| Rhyacotriton variegatus | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Amphibia |
| Order: | Urodela |
| Suborder: | Salamandroidea |
| Family: | Rhyacotritonidae Tihen, 1958 |
| Genus: | Rhyacotriton Dunn, 1920 |
| Species | |
|
Rhyacotriton cascadae (blue) | |
The torrent salamanders or Cascade salamanders are a family of salamanders (Rhyacotritonidae) with only one genus, Rhyacotriton. The torrent salamanders have highly reduced lungs and are endemic to the United States from northwestern Washington to northwestern California,[1][2] where they live in cool and shaded stream habitats in moist coniferous forests.[3]
Description
Maximum adult snout-vent length is 6 cm (2.4 in). They have complete metamorphosis, but a few neotenic traits have been found, like the presence of conical teeth and reduced or absent nasal bones. Nasal bones have never been seen in Rhyacotriton olympicus but are present in some specimens of the other species, and occurs most often in R. variegatus. The lungs are minute; in R. olympicus they are only 5–7 mm (0.2‒0.3 in.) in length, though highly vascular and filled with air.[4] They are very sensitive to desiccation and warm temperatures. More than 28 °C (83 °F) can be fatal, and they can tolerate a water loss of only 19.4% of initial body weight at most (compared to 29.0% to 32.9% for other species). Because of this, they are rarely found more than a meter away from free-running water. On rare occasions adults can be found under objects a few meters from water after heavy rain.[5][6][7][8] Males have a unique vent gland.[9]
Reproduction
Courtship is terrestrial. The male deposits a spermatophore on the ground, which is then picked up by the female.[10] The eggs have a pale yellow-white ova, and are deposited separately and haphazardly in slow-flowing water. Sometimes communal oviposition occurs.[11] They are attached neither to each other nor to the substrate, which is unique in salamanders. Parental care is absent.[12]
Species
The genus Rhyacotriton includes four species:
- Cascade torrent salamander (R. cascadae)
- Columbia torrent salamander (R. kezeri)
- Olympic torrent salamander (R. olympicus)
- Southern torrent salamander (R. variegatus)
Taxonomy
Originally the genus Rhyacotriton was placed in the family Ambystomatidae, later in the family Dicamptodontidae, and finally in 1992 it was placed into a family of its own. At the same time, genetic analysis provided evidence to split the only known species R. olympicus into four species.[12]
Intrinsic Phylogeny
Intrinsic Phylogeny of genus Rhyacotriton. [13]
References
- ^ Tree of Life: Rhyacotritonidae
- ^ Rose, C. S.; James, B. (2013). "Plasticity of lung development in the amphibian, Xenopus laevis". Biology Open. 2 (12): 1324–1335. doi:10.1242/bio.20133772. PMC 3863417. PMID 24337117.
- ^ Emel, Sarah L.; Olson, Deanna H.; Knowles, L. Lacey; Storfer, Andrew (2019). "Comparative landscape genetics of two endemic torrent salamander species, Rhyacotriton kezeri and R. variegatus: Implications for forest management and species conservation". Conservation Genetics. 20 (4): 801–815. Bibcode:2019ConG...20..801E. doi:10.1007/s10592-019-01172-6.
- ^ Dunn, Emmett Reid (July 30, 1920). "Notes on two Pacific Coast Ambystomidae". Proceedings of the New England Zoölogical Club. 7: 55–59. ISSN 0749-8934 – via Biodiversity Heritage Library.
- ^ Amphibians of Western North America
- ^ Geographic variation and speciation in the torrent salamanders of the genus Rhyacotriton (Caudata: Rhyacotritonidae)
- ^ ADW: Rhyacotritonidae: INFORMATION
- ^ The Biology of Amphibians and Reptiles in Old-Growth Forests in the Pacific Northwest
- ^ Reproductive Biology and Phylogeny of Urodela
- ^ Courtship in the Torrent Salamander, Rhyacotriton, has an Ancient and Stable History
- ^ Thompson, Curtis E; Foxx, Charles E; Ojala-Barbour, Reed; McIntyre, Aimee P; Hayes, Marc P (2018-12-01). "Olympic torrent salamander (Rhyacotriton olympicus) oviposition site with notes on early development". Northwestern Naturalist. 99 (3): 197–208. doi:10.1898/nwn17-29.1.short. Archived from the original on 2025-01-23.
- ^ a b "Rhyacotriton kezeri (Good & Wake, 1992)". amphibiaweb.org. Retrieved 2026-06-15.
- ^ Alexander Pyron, R.; J. Weins, John (12 June 2011). "A large-scale phylogeny of Amphibia including over 2800 species, and a revised classification of extant frogs, salamanders, and caecilians". Molecular Phylogenetics and Evolution. 61 (2). Elsevier: 543–583. doi:10.1016/j.ympev.2011.06.012. Retrieved 8 April 2025.