Plethodon glutinosusNorthern Slimy Salamander

Geographic Range

The slimy salamander has an extensive range throughout the eastern and central United States. Starting in central New York and the southern tip of Wisconsin, the range covers much of the eastern seaboard, moving southward to central Florida and the Gulf coast and westward to parts of east Texas and Oklahoma. It is notably absent from the lower Mississippi valley, presumably because flooding causes frequent disturbance to the preferred habitat of the slimy salamander in that region (Grobman 1944).

Habitat

The slimy salamander is commonly found beneath stones and decaying logs in wooded areas and alongside streams, as well as in the crevices of shale banks and along the sides of gullies and ravines (Davidson 1956; Grobman 1944). It generally moves about underground using animal and insect burrows (Cowley 1999). Mean home-range area is 3.01 +/- .613 sq. meters for adults and 3.46 +/- 1.851 sq. meters for juveniles (Marvin 1998).

Physical Description

The slimy salamander has mainly black skin, covered by abundant silver-white or brassy specks, or both; the ventrum has variable shades but is generally lighter than the dorsum. The organism is distinguished from other dark salamanders in its range by the presence of a nasolabial groove. More noticeably, P. glutinosus is defined by a slimy, glue-like secretion released from its skin glands. It has 16 costal grooves, on rare occurrences 15 or 17, and generally ranges from 4.75 to 6.75 inches in length (Conant and Collins 1998). Hatchlings are born with only slight dark coloration on the dorsum and none on the ventrum; melanin for the specks begins to appear on the dorsum after three days. Adult females exhibit slightly larger snout-to-vent lengths than adult males, but are otherwise similar in appearance (Highton 1956).

  • Average mass
    4.2 g
    0.15 oz
    AnAge
  • Average basal metabolic rate
    0.00191 W
    AnAge

Development

Reproduction

Breeding of P. glutinosus takes place at the beginning of April and eggs are deposited anytime from late spring in the northern part of the range to very late summer at the range's southern tip. Eggs are laid in moist areas such as caves or under the bark of rotting trees. Clutch size ranges from 4 to 12 eggs. Hatchlings emerge close to three months after eggs are deposited (Highton 1956). Juveniles have no aquatic stage and develop directly to adulthood, as the species is entirely terrestrial (Feder 1983).

Female slimy salamanders do not sexually mature until they are two years old, and cannot lay eggs until approaching age three. The same is true for most males, although some have been found capable of breeding at two years of age. In regions where the growing season is short, a wait of three years is almost certain before sexual maturity is reached (Highton 1962).

  • Key Reproductive Features
  • gonochoric/gonochoristic/dioecious (sexes separate)
  • Average number of offspring
    21
    AnAge
  • Average age at sexual or reproductive maturity (female)
    Sex: female
    910 days
    AnAge
  • Average age at sexual or reproductive maturity (male)
    Sex: male
    910 days
    AnAge

Lifespan/Longevity

Behavior

The slimy salamander is a territorial species, like most plethodontids. Individuals, both male and female, can become very aggressive in competition for space toward members of both their own species and competitor species (Marvin 1998). Females fiercely guard their clutches, in some instances neglecting to forage for food, and may abandon eggs if they discover any tampering at the nest site (Highton 1956).

Courtship consists of an elaborate dance performed by the male, detailed in Organ 1960. Notably, prior to the dance, the chin, feet, and white spots on the male will turn pink and later to a bright shade of red.

The slimy salamander is vulnerable to parasitism by some nematode worms, particularly when guarding an egg clutch, due to poor nutrition. The small activity range of the species also makes it a victim of predation by a number of snakes that occur in the geographical range or P. glutinosus (Highton 1956).

Food Habits

Prey of P. glutinosus consists mainly of ants (42%), followed by beetles (26%), sowbugs, and earthworms, depending on what is seasonally most prevalent (Davidson 1956).

Conservation Status

According to the U.S. Fisheries and Wildlife Service, the slimy salamander is considered neither a threatened nor endangered species throughout its range. However, some species within the P. glutinosus complex (see Other Comments) may be candidates for the endangered and threatened species lists (USFWS 1999).

Other Comments

Plethodon glutinosus is now taxonomically defined as a genetic complex consisting of at least thirteen species discernible only through laboratory testing, though many species are indistinguishable in the field and are therefore still considered for this project to be subspecies of a single lineage (Highton et al. 1989).

Contributors

James Yung (author), Michigan State University, James Harding (editor), Michigan State University.

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.

ectothermic

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

forest

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

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.

motile

having the capacity to move from one place to another.

native range

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

References

Conant, R., J. Collins. 1998. A field guide to reptiles & amphibians of eastern and central North America, 3rd ed., expanded. Boston: Houghton Mifflin Company.

Cowley, M. 1998. "'Native Florida'--Lungless salamanders" (On-line). Accessed November 12, 1999 at www.nsis.org/wildlife/amph/sal-lungless.html.

Davidson, J. 1956. Notes on the food habits of the slimy salamander _Plethodon glutinosus_. Herpetologica, 12(2): 129-131.

Feder, M. 1983. Integrating the ecology and physiology of plethodontid salamanders. Herpetologica, 39: 291-310.

Grobman, A. 1944. The distribution of the salamanders of the genus _Plethodon_ in eastern United States and Canada. Annals of the New York Academy of Science, 45: 261-316.

Highton, R. 1962. Geographic variation in the life history of the slimy salamander. Copeia, 1962: 597-613.

Highton, R. 1956. The life history of the slimy salamander, _Plethodon glutinosus_, in Florida. Copeia, 1956: 75-93.

Highton, R., G. Maha, L. Maxson. 1989. Biochemical evolution in the slimy salamanders of the _Plethodon glutinosus_ complex in the eastern United States. Illinois Biological Monographs, 57.

Marvin, G. 1998. Interspecific aggression and spatial relationships in the salamanders _Plethodon kentucki_ and _Plethodon glutinosus_: evidence of interspecific interference competition. Canadian Journal of Zoology, 76: 94-103.

Organ, J. 1960. The courtship and spermatophore of the salamander _Plethodon glutinosus_. Copeia, 1960: 34-40.

U.S. Fisheries and Wildlife Service, Division of Endangered Species, Branch of Information Management, 1999. Accessed November 12, 1999 at endangered.fws.gov/endspp.html.