Plethodontidae |  |
518 species in 28 genera
Commonly Called Lungless Salamanders
Plethodon shermani
Photo by Brad Moon
(Click for family gallery)The largest family of extant salamanders with over 500 species. All members of this family lack lungs, relying on cutaneous respiration instead, and possess naso-labial grooves, which aid in chemoreception. This group was once thought to have arisen out of the Appalachian Mountains in the eastern United States, which remains a biodiversity hotspot for this family. Members within this group have adapted to stream, arboreal, terrestrial, fossorial (underground) and cave habitats. Currently there are two subfamilies, the Hemidactylinae and Plethodontinae, of which the latter has species capable of ballistically projecting their tongue (along with tongue skeleton) to capture prey (as in Hydromantes) as well as having webbed feet (tribe Bolitoglossini). Generalized in body form with four fingers and five toes (except when reduced to four toes in miniaturized species), plethodontids cover the spectrum of salamander sizes. Most species are direct developers, with exceptions amongst members of the Desmognathus, Eurycea, Gyrinophilus, Hemidactylium, Pseudotriton, Stereochilus, and Urspelerpes genera.
With only a few of exceptions, this family is found in the New World and extends from southern Canada south through Bolivia and Brazil. The exceptions to the New World include species of the genus Hydromantes found in the Middle Western Mediterranean in Europe (other members of which also occur in California) and a single species known from Asia (Karsenia). It includes the only group of tropical salamanders which account for about 2/3 of the species and 40% of all salamanders.
News Highlight:
December 21, 2020: Salamanders differ from all other vertebrates in their range of genome size. At the lower end (about 9 picograms (pg)/haploid genome) they marginally overlap with frogs but the upper end is vastly greater and exceeds 100 pg. Because cell size is proportional to genome size, salamander cells can be enormous and this poses a problem for small species, which often show bizarre morphologies. This led to the concept of biological size, as contrasted with metrical or physical size. A study of tropical plethodontid salamanders (Decena-Segarra et al 2020), many of which are very small, reports genome sizes and calculates biological size (mean snout-vent/square root genome size) for 84 species, 60 newly studied. Many of these species are biologically smaller than their physical size would suggest. Biological size may be the most effective measurement for studying morphological consequences of miniaturization in taxa such as Thorius and Batrachoseps. (DW)
June 22, 2020: Plethodontid salamanders use protrusible, ballistic tongues that display high performance and work well in both cold and warm temperatures to capture prey. Deban et al (2020) show in a musculoskeletal and performance analysis that remarkable homoplastic evolution in the two major groups of plethodontid salamanders has transformed a muscle-powered, musculoskeletal system capable of only modest performance and subject to thermal sensitivity into an extreme-performance, spring-powered system that is thermally robust. Extreme examples exceed available muscle power using an elastic-recoil mechanism. Intermediate forms are not found, suggesting that incipient elastic forms maybe short-lived. The result is a rich array of functional patterns of tongue use in feeding, with remarkably specialized end points. See a video of the cold-proof tongue in action (DW)
February 25, 2019: Most salamanders must breath in both water and air so they use gills, lungs, skin, and other organs for breathing at various times during development. Plethodontid salamanders, also known as lungless salamanders, do not even have lungs and rely heavily on breathing through their skin and an area near the back of their mouth. Until recently, the molecular changes that allow lungless salamanders to efficiently breath through their skin have remained completely unknown. Lewis et al. (2018) show that lungless salamanders express a novel paralogue of the gene surfactant-associated protein C (SFTPC) within areas (such as the skin) that lungless salamanders use to breathe. In other vertebrates, SFTPC is critical for gas exchange in the lungs and is expressed only in the lungs. This new paralogous gene appears to be found only in salamanders, but, similar to SFTPC, in lunged salamanders it is expressed only in the lung. Lewis et al. (2018) propose that this new gene paralogue may be one reason lungless salamanders have thrived and account for more than two-thirds of salamander species. (M Womack)
July 23, 2018: How will salamanders deal with climate change? A new experimental study (Riddell et al. 2018) found that plethodontid salamanders show remarkably plastic responses to ecological conditions, which bode well for anticipated increases in climatic temperatures. The study integrated experimental physiology and behavior into a mechanistic species distribution model and predicted extinction risk based on the capacity of individual salamanders to maintain energy balance both with and without plasticity. The important conclusion is that incorporating plasticity fundamentally alters ecological predictions by reducing risk of extinction. These findings help understand how salamanders in the southern Appalachian biodiversity hotspot dealt effectively with Pleistocene climatic events. They likely "sheltered in place", as suggested by the many phylogeographic studies showing substantial geographic structuring of genetic variation. Read the press release. (DW)March 14, 2016: Plethodontid salamanders are more agile than other salamanders and they are known to jump, especially to escape predation. Ryerson et al. (2016) studied jumping in six species (three genera). All were capable of jumping by lateral body bending followed by rapid straightening, which propels the salamander into the air. Most likely force to propel the animal is applied through one or both hind limbs. Salamanders jumped a maximum of 1.8 times head+body length and jump height is scaled with body size and forelimb length. Species did not differ in any other aspects of performance, except takeoff velocity where longer salamanders are slower. No correlation was found between tail length, or even presence of a tail, and any variable. Further kinematic analysis is needed to understand how salamanders maintain jumping performance no matter the size. (DW)
November 28, 2016: Minute salamanders of the genus Thorius were once very common in montane habitats bordering the eastern and southern margins of the Mexican Plateau, where they have experienced an adaptive radiation in miniature. Molecular data have proven to be essential for sorting specimens into species, which are then discerned to differ in morphology, ecology, elevational distribution, etc. Species detection is an ongoing activity, made difficult by the increasing rarity of these tiny animals. Parra-Olea et al. (2016) revises the taxonomy of the southern and easternmost members of the genus in Oaxaca, Mexico, redescribing two species while describing and naming three others. The new species all are considered to be critically endangered, and the entire genus appears to be on the brink of extinction from as yet undetermined causes. (DW)
Written by AmphibiaWebNotable Family Characteristics
- All species are lungless
- Species have diversified into a wide variety of habitats, such as stream, arboreal, terrestrial, fossorial (underground) and cave habitats
- Morphological characters include: 1) pterygoid absent; 2) naso-labial groove present; 3) lacrimals absent; 4) otic and occipital elements fused; 5) elongate, up to 60 vertebrae; 6) teeth have a distinct crown and pedicel; 7) males possess a mental gland
- Fertilization internal
- Direct development in most species
- Distribution predominantly North America through South America to Bolivia and Brasil, with exceptions of one genus in Korea (Karsenia) and some species of Hydromantes in Europe
Cartography Credit: Zoe Yoo, UC Berkeley
Range maps sources: AmphibiaWeb, UC Berkeley, and IUCN RedListRelevant Reference
Larson, Allan, David Wake, and Tom Devitt. 2006. Plethodontidae. Lungless Salamanders. Version 26 September 2006. http://tolweb.org/Plethodontidae/15441/2006.09.26 in The Tree of Life Web Project, http://tolweb.org/
Parra-Olea G, Rovito SM, García-París M, Maisano JA, Wake DB, Hanken J. 2016. Biology of tiny animals: three new species of minute salamanders (Plethodontidae: Thorius) from Oaxaca, Mexico. PeerJ 4:e2694 https://doi.org/10.7717/peerj.2694
Shen, X., D. Liang, M. Chen, R.-L. Mao, D. B. Wake, and P. Zhang. 2016. Enlarged multilocus data set provides surprisingly younger time of origin for the Plethodontidae, the largest family of salamanders. Systematic Biology 65: 66–81.
Wake, D. B. 1966. Comparative osteology and evolution of the lungless salamanders, family Plethodontidae. Memoirs of the Southern California Academy of Sciences 4: 1–111.
Wake, D. B. 2012. Taxonomy of salamanders of the family Plethodontidae (Amphibia: Caudata). Zootaxa 3484: 75–82.
Subfamily Hemidactyliinae (395 species)
Genus Aquiloeurycea (6 species) [subfamily Hemidactyliinae]
Aquiloeurycea cafetalera account photos no sound/video Aquiloeurycea cephalica no account photos no sound/video Aquiloeurycea galeanae no account photos no sound/video Aquiloeurycea praecellens no account no photos no sound/video Aquiloeurycea quetzalanensis no account photos no sound/video Aquiloeurycea scandens no account photos no sound/video
Genus Batrachoseps (23 species) [subfamily Hemidactyliinae]
Genus Bolitoglossa (141 species) [subfamily Hemidactyliinae]
Genus Bradytriton (1 species) [subfamily Hemidactyliinae]
Bradytriton silus account photos no sound/video
Genus Chiropterotriton (23 species) [subfamily Hemidactyliinae]
Genus Cryptotriton (7 species) [subfamily Hemidactyliinae]
Cryptotriton alvarezdeltoroi no account photos no sound/video Cryptotriton monzoni account photos no sound/video Cryptotriton nasalis account photos no sound/video Cryptotriton necopinus account no photos no sound/video Cryptotriton sierraminensis account photos no sound/video Cryptotriton veraepacis no account photos no sound/video Cryptotriton xucaneborum account photos no sound/video
Genus Dendrotriton (8 species) [subfamily Hemidactyliinae]
Dendrotriton bromeliacius no account photos no sound/video Dendrotriton chujorum account photos no sound/video Dendrotriton cuchumatanus no account photos no sound/video Dendrotriton kekchiorum no account photos no sound/video Dendrotriton megarhinus account photos no sound/video Dendrotriton rabbi no account photos no sound/video Dendrotriton sanctibarbarus account photos no sound/video Dendrotriton xolocalcae no account photos no sound/video
Genus Eurycea (34 species) [subfamily Hemidactyliinae]
Genus Gyrinophilus (4 species) [subfamily Hemidactyliinae]
Gyrinophilus gulolineatus account photos no sound/video Gyrinophilus palleucus account photos no sound/video Gyrinophilus porphyriticus account photos no sound/video Gyrinophilus subterraneus account photos no sound/video
Genus Hemidactylium (1 species) [subfamily Hemidactyliinae]
Hemidactylium scutatum account photos no sound/video
Genus Isthmura (7 species) [subfamily Hemidactyliinae]
Isthmura bellii account photos no sound/video Isthmura boneti no account photos no sound/video Isthmura corrugata account photos no sound/video Isthmura gigantea no account photos no sound/video Isthmura maxima account photos no sound/video Isthmura naucampatepetl account photos no sound/video Isthmura sierraoccidentalis no account photos no sound/video
Genus Ixalotriton (2 species) [subfamily Hemidactyliinae]
Ixalotriton niger account photos no sound/video Ixalotriton parvus account photos no sound/video
Genus Nototriton (22 species) [subfamily Hemidactyliinae]
Genus Nyctanolis (1 species) [subfamily Hemidactyliinae]
Nyctanolis pernix account photos no sound/video
Genus Oedipina (40 species) [subfamily Hemidactyliinae]
Genus Parvimolge (1 species) [subfamily Hemidactyliinae]
Parvimolge townsendi account photos no sound/video
Genus Pseudoeurycea (41 species) [subfamily Hemidactyliinae]
Genus Pseudotriton (2 species) [subfamily Hemidactyliinae]
Pseudotriton montanus account photos no sound/video Pseudotriton ruber account photos no sound/video
Genus Stereochilus (1 species) [subfamily Hemidactyliinae]
Stereochilus marginatus account photos no sound/video
Genus Thorius (29 species) [subfamily Hemidactyliinae]
Genus Urspelerpes (1 species) [subfamily Hemidactyliinae]
Urspelerpes brucei account photos no sound/video
Subfamily Plethodontinae (123 species)Genus Aneides (10 species) [subfamily Plethodontinae]
Aneides iecanus account photos no sound/video Aneides klamathensis account photos no sound/video Aneides niger account photos no sound/video Aneides (Aneides) ferreus account photos no sound/video Aneides (Aneides) flavipunctatus account photos no sound/video Aneides (Aneides) hardii account photos no sound/video Aneides (Aneides) lugubris account photos sound/video Aneides (Aneides) vagrans account photos sound/video Aneides (Castaneides) aeneus account photos no sound/video Aneides (Castaneides) caryaensis account photos no sound/video
Genus Desmognathus (39 species) [subfamily Plethodontinae]
Genus Ensatina (1 species) [subfamily Plethodontinae]
Ensatina eschscholtzii account photos sound/video
Genus Hydromantes (13 species) [subfamily Plethodontinae]
Hydromantes (Atylodes) genei account photos no sound/video Hydromantes (Hydromantes) brunus account photos sound/video Hydromantes (Hydromantes) platycephalus account photos sound/video Hydromantes (Hydromantes) samweli account photos no sound/video Hydromantes (Hydromantes) shastae account photos no sound/video Hydromantes (Hydromantes) wintu account photos no sound/video Hydromantes (Speleomantes) ambrosii account photos no sound/video Hydromantes (Speleomantes) flavus account photos no sound/video Hydromantes (Speleomantes) imperialis account photos no sound/video Hydromantes (Speleomantes) italicus account photos no sound/video Hydromantes (Speleomantes) sarrabusensis no account photos no sound/video Hydromantes (Speleomantes) strinatii account photos no sound/video Hydromantes (Speleomantes) supramontis account photos no sound/video
Genus Karsenia (1 species) [subfamily Plethodontinae]
Karsenia koreana account photos no sound/video
Genus Phaeognathus (1 species) [subfamily Plethodontinae]
Phaeognathus hubrichti account photos no sound/video
Genus Plethodon (58 species) [subfamily Plethodontinae]
Citation: AmphibiaWeb: Information on amphibian biology and conservation. [web application]. Berkeley, California: AmphibiaWeb. Available: https://amphibiaweb.org/. (Accessed:AmphibiaWeb's policy on data use.