Pseudotriton ruber

Geographic Range

Pseudotriton ruber , the red salamander, is native in the Nearctic region of the world. The red salamander is found in the eastern United States ranging as far north as New York southward along the Appalachian range through Ohio, West Virginia, Virginia, Kentucky, and Tennessee. Its range extends southward to the Gulf Coast of Louisiana, Alabama, and the western panhandle of Florida, and can also be located towards the southeast area of the Mississippi River. The red salamander is absent in Coastal Plain of Virginia, North and South Carolina, and Georgia.

• Biogeographic Regions
• nearctic nearctic
  • native native

Habitat

Red salamanders are mainly nocturnal, commonly found in or around slow-moving cold streams and springs all along the eastern coast from sea level up to 1500 meters. In adulthood, red salamanders are mostly aquatic and found in deeper springs where temperatures remain constant in the fall and winter season. In the spring and summer seasons, they migrate and take shelter under logs, stones, and leaf masses in deciduous or mixed forest in more terrestrial regions. During rainy nights, they can be spotted foraging around but usually try to remain hidden in shelter. Female red salamanders can also be found inhabiting caves to lay their eggs. Juvenile red salamanders typically stay in the steams for up to 3.5 years before they develop into adults.

• Habitat Regions
• terrestrial terrestrial
• freshwater freshwater

• Terrestrial Biomes
• mountains mountains

• Aquatic Biomes
• rivers and streams

• Other Habitat Features
• caves

Physical Description

Red salamanders are plethodontid salamanders, meaning they lack lungs. Fully-developed adults can be 11 to 18 centimeters in total length. They have a bright orange-red to red dorsum with black spots scattered around their body, with the chin region appearing black. Red salamanders also have a short tail and contain around 16 grooves along their body. Male and female red salamanders are very similar in appearance, with the female being slightly bigger. Older red salamanders can lose their bright red color, changing to a more purplish-brown pigment along with more enlarged spots. The species is also ectothermic, like all other salamanders.

During their larval stage, which can last for 1-3.5 years, can range in growth from 4.5-5 centimeters. Before developing their distinctive bright red color, larval red salamanders are purplish brown on their upper surface and have a yellowish underside with black spots scattered throughout the back, sides, and tail.

Their aposematic color closely resembles the poisonous eastern newt ( Notophthalmus viridescens ). As both species are toxic, predators avoid them. Red salamanders often get confused with another plethodontid salamander, the mud salamander ( Pseudotriton montanus ). They both have bright red dorsums with black spots throughout their body. To distinguish the two, red salamanders have a yellow iris and a longer snout than that of the mud salamander.

• Other Physical Features
• ectothermic ectothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• female larger

Development

During the autumn season when a female red salamander lays her eggs, incubation can last for 2 to 3 months until they are hatched. Once hatched, the hatchlings can average 11 to 14 millimeters snout-vent length (SVL). Depending on the location and water temperatures, average annual growth rates can differ for the species. During the first 6 months, larval populations in coastal areas can be found to grow 1.2-2.0 millimeters per month. At higher elevations (e.g. in Piedmont regions) populations only grow about 1.2 millimeters per month. For the next 2 to 3 years, the total length the red salamander can grow is 10-12 millimeters SVL. The larval period can last from 1.5-3.5 years, depending on the location. In coastal regions, the larval period lasts 18-23 months, whereas in higher elevations the larval period lasts 31-33 months. The longest larval periods have been found in populations in New York, where red salamanders do not reach adulthood for 3.5 years.

Metamorphosis from tadpole to adult occurs between April and November, nut is most common from April to July. Male red salamanders are considered to be mature when they reach 53-63 millimeters SVL, and females at 55-68 millimeters SVL.

• Development - Life Cycle
• metamorphosis metamorphosis

Reproduction

During the breeding season red salamanders are polygynandrous, meaning both the male and female can have multiple mates. Courtship between the male and female red salamander consist of the male approaching the female first, rubbing his snout along her snout, cheeks, and underneath her chin. This behavior is common to other plethodontids. The male then advances his head and body underneath her chin and begins to undulate his tail. If sexually-receptive, the female will place her chin against the base of the male's tail and will straddle it. Then the two will engage in this tail-straddle walk for around 2 minutes until the male releases his spermatophore. Males will normally deposit at most two spermatophores per night. Once the spermatophore is released, the male will place his cloaca on the substrate and in a rhythm like fashion contract his cloaca region while undulating his tail violently. To lead the female over the spermatophore, the male will raise and arch his tail and flex it from side to side. The male will continue this until the female moves over the spermatophore and picks it up. After the female has picked up the sperm packet, the two separate soon after.

• Mating System
• polygynandrous (promiscuous) polygynandrous (promiscuous)

Red salamanders are oviparous. They reach sexual maturity between 43 to 48 months after hatching. Adult red salamanders typically breed year-round except for the coldest months (December to Febrauary).

The male drops his spermatophore (sperm packet) externally and the female picks it up, so that internal fertilization can occur. The female is capable of storing the sperm for a long period of time before laying her eggs. The female will wait until conditions are suitable for her to dispatch her eggs, which is typically in the autumn season. Clutch sizes can range from 29-130 eggs, and egg masses are found on the undersides of rocks or stones that are in or near water. Incubation periods last from 2 to 3 months, with the eggs hatching from mid-December to mid-February. Once hatched, the newborn red salamanders are independent.

• Key Reproductive Features
• iteroparous iteroparous
• year-round breeding year-round breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• fertilization fertilization
  • internal internal
• oviparous oviparous
• sperm-storing sperm-storing

The female Pseudotriton ruber is the primary parental care provider for the eggs. In preparation for oviposition, the female will position herself upside down in order to lay her eggs on the underside of a rock or stone. Once the eggs have been laid, the female provides the protection from predators and other females until the eggs hatch and then parental care ceases.

• Parental Investment
• female parental care female parental care
• pre-hatching/birth
  • provisioning
    • female
  • protecting
    • female

Lifespan/Longevity

Red salamanders can live approximately 20 years in captivity. Little information is known about their longevity in the wild.

Behavior

The red salamander is a nocturnal species. Unlike the mainly sedentary, aquatic larval stages, the adults migrate from the streams to terrestrial regions in the spring season. They will then return to the streams in the late summer or fall for breeding. During the winter months, this species may be difficult to locate, suggesting it hibernates.

During the breeding season, males are not aggressive towards each other. Instead, males may actually court other males. This behavior is thought to be more of a sexual interference rather than the inability to recognize the opposite sex. The male tries to cause another male into releasing unnecessary spermatophores.

• Key Behaviors
• terricolous
• nocturnal nocturnal
• motile motile
• migratory migratory
• sedentary sedentary

Home Range

Not much is known about Pseudotriton ruber home range. It is not known to be a territorial species, and is often found living with other salamanders under the same shelter.

Communication and Perception

As with many plethodontid salamanders, the male red salamander possess a hedonic gland. The hedonic gland is usually short, vertically oriented, and in a circular cluster located near the tip of the chin. This gland plays a role in the courtship of the species by secreting a sexual stimulant. Red salamanders also possess a naso-labial groove, a shallow, vertical groove with a slight curvature extending down the mouth. Though not much is known about the perception of this gland, it is believed that the naso-labial groove plays a direct role in stimulating the salamander's chemoreception, which is thought to play a role in reproduction. Plethodontid salamanders also rely on chemical cues to recognize home ranges, territories, and the sex of potential mates.

• Communication Channels
• chemical chemical

• Perception Channels
• visual visual
• chemical chemical

Food Habits

Larval red salamanders are often feeding and foraging throughout the year in aquatic habitats. In the first 2-3 years of their lives, they mostly consume many aquatic flies (e.g., larval Chironomid flies), crustaceans, and other aquatic insect and salamander larvae. They will continue this diet until they develop into adulthood. As adults, red salamanders will eat many aquatic and terrestrial insects, such as water beetles (Family Dytiscidae), and earthworms. They will also consume snails, slugs, spiders, and other small salamanders such as the eastern red-backed salamander Plethodon cinereus .

The red salamander uses a tongue protraction ability to capture its prey. Upon seeing potential prey, the red salamander will extend its tongue, which consists of a tongue skeleton, by the use of its "m.subarcualis rectus (SAR)"(Deban and Dicke, 1999), the primary tongue protractor muscle, to capture the insect on its tongue pad, located at the end of the tongue. After the red salamander has successfully captured its prey, it retracts its tongue with the use of its "m. rectus cervicis profundus (RCP)"(Deban and Dicke, 1999) muscle.

• Primary Diet
• carnivore carnivore
  • eats terrestrial vertebrates
  • insectivore insectivore
  • eats non-insect arthropods
  • molluscivore molluscivore
  • vermivore

• Animal Foods
• amphibians
• insects
• terrestrial non-insect arthropods
• mollusks
• terrestrial worms

Predation

There are little data available about known predators of Pseudotriton ruber . Probable predators may include raccoons ( Procyon lotor ), some woodland birds, the striped skunk ( Mephitis mephitis ), and some species of shrews and snakes. Also, other salamanders have been found to feed on larval red salamanders.

Red salamanders have a bright red color indicating their toxicity. This aposematic coloration is common to poisonous and noxious species. Many predators avoid these species after initial contact. When threatened by a predator, the red salamander will assume a defensive posture of curling its body. This action elevates the rear limbs and tail while swaying the tail in a wave-like motion from side to side. This occurs while the red salamander tucks its head underneath the tail.

• Anti-predator Adaptations
• aposematic aposematic

Ecosystem Roles

The red salamander plays an ecological role as a predator and prey. They also play host to many protozoans, trematodes, and cestode parasites. Some examples of protozoans found on both larval and adult salamanders include Cryptobia borreli , Cyamoeba bacterifera , Eutrichomastix batrachorum , Hexamastix batrachorum , Heamitus intestinalis , Karotomorpha swezi , Prowazekella longifilis , and Tritrichomonas augusta . Common trematodes found are Allocreadium pseudotritoni , Brachycoelium hospitale , and Gorgoderina bilobata . Only adult red salamanders host the cestode Crepidobothrium cryptobranchi .

The red salamander can be found living in the company of other salamander species such as the southern Eurycea cirrigera or northern two-lined salamander Eurycea bislineata and mountain dusky salamander Desmognathus ochrophaeus .

Economic Importance for Humans: Positive

Although not much is known about how red salamanders benefit humans, this species is sometimes kept as a pet.

• Positive Impacts
• pet trade pet trade

Economic Importance for Humans: Negative

There is no known adverse economic effect of Pseudotrition ruber on humans.

Conservation Status

Red salamanders are listed as endangered in the state of Indiana, a "Species of Special Concern" in Louisiana, and as "Protected" in New Jersey. Despite this, they are typically found in protected areas and are listed as a species of "least concern" by the IUCN Red List.

Because this species lives in woodland areas and clean streams, this species is impacted by pollution, deforestation, acid drainage from coal mines, and stream siltation.

Other Comments

The defensive posture displayed by red salamanders when provoked has been hypothesized by a study Howard and Brodie (1972) to be a possible Batesian mimicry of the red eft stage of eastern newt ( Notophthalmus viridescens ). Critics of this hypothesis state that prey would have relative ease distinguishing between red salamanders and the red eft because the red salamander is much larger. Also, like the red eft, red salamanders produce their own toxic protein secretions called PTTX (pseudotritontoxin) that they use as defense. More critics have stated that the defensive postures red salamanders use are more similar to related plethondontids than to newts.

Additional Links

AmphibiaWeb

Encyclopedia of Life

Contributors

Ricky Miller (author), Radford University, Karen Powers (editor), Radford University, April Tingle (editor), Radford University, Emily Clark (editor), Radford University, Cari Mcgregor (editor), Radford University, Jacob Vaught (editor), Radford University.

References

Brodie, Jr., E., R. Howard. 1972. Behavioral mimicry in the defensive displays of the urodele amphibians Nophthalmus viridescens and Pseudotriton ruber. BioScience , 22/11: 666-667.

Brown, C., B. Martof. 1996. The function of the naso-labial groove of Plethodontid salamanders. Physiological Zoology , 39/4: 357-367.

Brown, C. 1968. Additional observations on the function of the nasolabial grooves of Plethodontid salamanders. Copeia , 1968/4: 728-731.

Bruce C., R. 2003. Ecological distribution of the salamanders Gyrinophilus and Pseudotriton in a southern Appalachian watershed. Herpetologica , 59/3: 301-310.

Bruce C., R. 1974. Larval development of the salamanders Pseudotriton montanus and P. ruber. American Midland Naturalist , 92/1: 173-190.

Cambell Grant, E., A. Wiewel, K. Rice. 2014. Stream-water temperature limits occupancy of salamanders in mid-Atlantic protected areas. Journal of Herpetology , 48/1: 45-50.

Cecala, K., S. Price, M. Dorcas. 2007. Diet of larval red salamanders (Pseudotriton ruber) examined using a nonlethal technique. Journal of Herpetology , 41/4: 741-745.

Dawley, E. 1992. Sexual dimorphism in a chemosensory system: The role of the vomeronasal organ in salamander reproductive behavior. Copeia , 1992/1: 113-120.

Deban, S., U. Dicke. 1999. Motor control of tongue movement during prey capture in plethodontid salamanders. The Journal of Experimental Biology , 202/24: 3699-3714.

Gustafson, M. 1993. Intraguild predation among larval plethodontid salamanders: A field experiment in artificial stream pools. Oecologia , 96/2: 271-275.

Hammerson, G., J. Garcia Moreno. 2014. "Pseudotriton ruber" (On-line). The IUCN Red List of Threatened Species. Accessed January 29, 2015 at http://www.iucnredlist.org/details/59404/0 .

Harding, J. 1997. Amphibians and Reptiles of the Great Lakes Region . Michigan: The University of Michigan Press.

Lannoo, M. 2005. Amphibian Declines: The Conservation Status of United States Species . California: University of California Press.

Martof, B., W. Palmer, J. Bailey, J. Harrison III. 1980. Amphibians and Reptiles of the Carolinas and Virginia . Chapel Hill, NC: The University of North Carolina Press.

Marvin A., G. 2003. Aquatic and terrestrial locomotor performance in a semiaquatic plethodontid salamander (Pseudotriton ruber): Influence of acute temperature, thermal acclimation, and body size. Copeia , 2003/4: 704-713.

Miller, B., M. Niemiller, G. Reynolds. 2008. Observations on egg-laying behavior and interactions among attending female red salamanders (Pseudotriton ruber) with comments on the use of caves by this species. Herpetological Conservation and Biology , 3/2: 203-210.

Mitchell, J., K. Reay. 1999. Atlas of Amphibians & Reptiles in Virginia . Richmond, VA: Virginia Department of Game and Inland Fisheries.

Mount, R. 1996. The Reptiles and Amphibians of Alabama . Tuscaloosa, AL: The University of Alabama Press.

Organ, J., D. Organ. 1968. Courtship behavior of the red salamander, Pseudotriton ruber. Copeia , 1968/2: 217-223.

Petranka, J. 2010. Salamanders of the United States and Canada . Washington, DC: Smithsonian Institution.

Sever, D. 1976. Morphology of the mental hedonic gland clusters of Plethodontid salamanders (Amphibia, Urodela, Plethodontidae). Journal of Herpetology , 10/3: 227-239.

Wilson, L. 1995. Land Manager's Guide to the Amphibians and Reptiles of the South . Durham, NC: The Nature Conservancy.