Desmognathus wrightiPygmy Salamander

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Geographic Range

Pygmy salamanders can be found in mountainous areas ranging from the Blue Ridge Mountains to the Great Smoky Mountains in the eastern United States. They are found most frequently in southwestern Virginia to the Georgia state line in southwestern North Carolina. (Mitchell and Reay, 1999; Petranka, 1998; Wilson, 1995)

Habitat

Pygmy salamanders are found in humid forested areas and can be found under mosses and rotten logs. Dense populations of pygmy salamanders occur most often in highly elevated spruce-fir forests, but also occur in hardwood forests in lower elevations. Elevations range from 800 m to 4500 m. (Martof, et al., 1980; Petranka, 1998; Wilson, 1995)

  • Range elevation
    800 to 4500 m
    2624.67 to 14763.78 ft

Physical Description

Adult pygmy salamanders range in size from 30 to 51 mm. They can primarily be identified by their distinctive coppery red stripe that extends along the body to the rounded tail. The rounded tail is less than half of total body length. The eyelids are also a copper color, which is a trait that distinguishes pygmy salamanders from related species. At sexual maturity females tend to be larger than males. (Conant, 1958; Hining and Bruce, 2005; Petranka, 1998; Wilson, 1995)

  • Sexual Dimorphism
  • female larger
  • Range length
    30 to 51 mm
    1.18 to 2.01 in

Development

After hatching, pygmy salamanders resemble small adults. Gills that were used during the embryonic stage of development are reabsorbed immediately prior to hatching as well as caudal fins. Pygmy salamanders, which are commonly identified by their rounded tail end, are indistinguishable from other species of salamanders in the embryonic stage due to the compressed tail in the egg. (Martof, et al., 1980; Organ, 1961)

Reproduction

Mating occurs twice a year during the fall and spring months. Adult male pygmy salamanders produce courtship pheromones to a desired female. In order for a male to mate with a female, the male salamander must use his jaws to attach himself to a female’s tail. This ritual is primary done to restrain the female and keep her from finding another mate. (Organ, 1961; Petranka, 1998)

Male pygmy salamanders deposit a spermatophore (a gelatinous package including sperm) on the ground, after which the female will take it into her cloaca. Females typically deposit eggs in a cluster during the late summer. Ideally, females deposit their eggs close to a permanent body of water, either a lake or a stream, but at higher elevations where standing water is absent, female salamanders lay their eggs on moist ground. Females lay an average of 10 eggs. Hatching usually occurs in mid to late October. Once hatched, the young are immediately independent and reach sexual maturity at 3.5 years for females and 4.5 years for males. (Organ, 1961; Petranka, 1998; Wilson, 1995)

  • Breeding interval
    Breeding can occur twice yearly.
  • Breeding season
    Pygmy salamanders breed in the late fall and late spring months.
  • Range number of offspring
    5 to 10
  • Average time to hatching
    2 months
  • Average age at sexual or reproductive maturity (female)
    4.5 years
  • Average age at sexual or reproductive maturity (male)
    3.5 years

Male pygmy salamanders do not play any role in helping with their young. However, females tend to eggs and to newly hatched salamanders. (Petranka, 1998)

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

Lifespan/Longevity

Although there is not any data on longevity of pygmy salamanders, other salamanders in the Desmognathus range in longevity from 15 to 20 years in captivity. (de Magalhaes and Costa, 2009)

Behavior

Pygmy salamanders are nocturnal and solitary. They are very sedentary, mainly moving between elevations during breeding season. During nights where the humidity is especially high, they perch on plants where they feed. Seasonally, these salamanders relocate underground to conserve moisture. (Petranka, 1998)

Home Range

Pygmy salamanders are motile, there is no data referring to how much pygmy salamanders move throughout their terrestrial environment.

Communication and Perception

Adult male pygmy salamanders produce courtship pheromones only to a desired female. Courtship pheromones are produced in the mental gland of the salamander. Also used in courtship are nasolabial grooves that are located in the snout of the salamander. These nasolabial grooves contain water born chemicals that are sent through nasal passages to the sensory epithelium. (Brown, 1968; Houck, 2008)

Food Habits

Pygmy salamanders primarily feed at night on small arthropods in the soil and leaf litter. (Wilson, 1995)

  • Animal Foods
  • insects
  • terrestrial non-insect arthropods

Predation

Spring salamanders (Gyrinophilus porphyriticus) and carabid beetles are major predators of pygmy salamander. Pygmy salamanders become immobile when threatened, becoming less appealing to predators. Pygmy salamanders are cryptically colored and tend to spend much of their time under cover to avoid detection. (Petranka, 1998; Petranka, 1998)

  • Anti-predator Adaptations
  • cryptic

Ecosystem Roles

Pygmy salamanders are the most terrestrial species of salamander in the genus Desmognathus. All Desmognathus salamanders have different life cycles, body sizes, and behaviors, and are considered to inhabit different niches. All Desmognathus species are affected by a common leech parasite, Oligobdella biannulata. These leeches, when latched on to the body of a salamander, transfer trypanosome protozoans called trypanosome, which infect the blood stream of the salamander host. (Goater, 2000; Petranka, 1998; Wilson, 1995)

Commensal/Parasitic Species

Economic Importance for Humans: Positive

Pygmy salamanders are often studied in the wild for their reproductive strategy and reproductive behavior. These salamanders are also researched from an evolutionary standpoint to understand how they live in higher elevations compared to other species of salamanders. (Petranka, 1998; Wilson, 1995)

  • Positive Impacts
  • research and education

Economic Importance for Humans: Negative

Unlike some other species of salamanders, pygmy salamanders do not survive well in captive situations. (Huheey and Stupka, 1960; Petranka, 1998)

Conservation Status

Pygmy salamanders are fairly common in spruce-fir forests of the southern Appalachians. These salamander populations are well conserved in Virginia and are listed as a species of least concern. (Hammerson, 2009; Petranka, 1998; Wilson, 1995)

Contributors

Cecilia de la Garza (author), Radford University, Karen Powers (editor), Radford University, Tanya Dewey (editor), University of Michigan-Ann Arbor.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

carnivore

an animal that mainly eats meat

chemical

uses smells or other chemicals to communicate

cryptic

having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.

ectothermic

animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature

female parental care

parental care is carried out by females

fertilization

union of egg and spermatozoan

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

heterothermic

having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.

insectivore

An animal that eats mainly insects or spiders.

internal fertilization

fertilization takes place within the female's body

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

metamorphosis

A large change in the shape or structure of an animal that happens as the animal grows. In insects, "incomplete metamorphosis" is when young animals are similar to adults and change gradually into the adult form, and "complete metamorphosis" is when there is a profound change between larval and adult forms. Butterflies have complete metamorphosis, grasshoppers have incomplete metamorphosis.

monogamous

Having one mate at a time.

motile

having the capacity to move from one place to another.

mountains

This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nocturnal

active during the night

oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

pheromones

chemicals released into air or water that are detected by and responded to by other animals of the same species

scent marks

communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them

seasonal breeding

breeding is confined to a particular season

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

solitary

lives alone

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

visual

uses sight to communicate

References

Brown, C. 1968. Additional Observations on the Function of the Nasolabial Grooves of Plethodontid Salamanders. Copia, 4: 728-731.

Bruce, R. 1977. The Pygmy Salamander, Desmognathus wrighti (Amphibia, Urodela, Plethodontidae), in the Cowee Mountains, North Carolina. Herpetology, 11: 246-247.

Conant, R. 1958. A Field Guide to Reptiles and Amphibians. Boston: Houghton Mifflin Company.

Goater, T. 2000. The Leech, Oligobdella Biannulata (Glossiphoniidae) on Desmognathine Salamanders: Potential for Trypanosome Transmission?. American Midland Naturalist: 434-438.

Hammerson, G. 2009. "http://www.iucnredlist.org/" (On-line). Accessed February 01, 2010 at http://www.iucnredlist.org/apps/redlist/details/59259/0.

Hining, K., R. Bruce. 2005. Population Structure and Life History Attributes of Syntopic Populations of the Salamanders Desmognathus aeneus and Desmognathus wrighti (Amphibia: Plethodontidae). Southeastern Naturalist, 4: 679-688.

Houck, L. 2008. Pheromone Communication in Amphibians and Reptiles. Annual Review of Physiology, 71: 161-176.

Huheey, J., A. Stupka. 1960. Amphibians and Reptiles of Great Smoky Mountains National Park. Knoxville Tennessee: The University of Tennessee Press.

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

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

Organ, J. 1961. Life History of the Pigmy Salamander, Desmognathus wrighti, in Virginia. American Midland Naturalist, 66: 384-390.

Petranka, J. 1998. Salamanders of the United States and Canada. Washington and London: Smithsonian Institution Press.

Tilley, S., J. Bernardo. 1993. Life History Evolution in Plethodontid Salamanders. Herpetologica, 49: 154-163.

Tilley, S., J. Harrison. 1969. Notes on the Distribution of the Pygmy Salamander, Desmognathus wrighti King. Herpetologica, 25: 178-180.

Welsh, H., S. Droege. 2001. A Case for Using Plethodontid Salamanders for Monitoring Biodiversity and Ecosystem Integrity of North American Forests.. Conservation Biology, 15: 558-569.

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

de Magalhaes, J., J. Costa. 2009. A database of vertebrate longevity records and their relation to other life-history traits.. Journal of Evolutionary Biology, 22: 1770-1774.