Eurycea lucifugaCave Salamander

Geographic Range

Cave salamanders (Eurycea lucifuga) are found throughout the eastern United States. Their range stretches from northeastern Oklahoma to western Virginia. Populations of cave salamanders are more concentrated in the Appalachian Mountain range, reaching from Alabama to northern Virginia. Another dense area includes a span extending through southern Indiana, Kentucky and middle to eastern Tennessee. The westernmost part of their range covers mid to southern Missouri, northeastern Oklahoma and northern Arkansas. (Briggler and Prather, 2006; Camp, et al., 2014; Lanoo, 2005; Petranka, 2010)

Habitat

Cave salamanders are troglophiles, meaning they can live entirely in caves and depend on cave-like conditions to complete their life cycles. Cave salamanders are mainly found in moist, dark places such as caves, or under rocks and logs. They have been reported in rock crevices along riversides. In southern Illinois adults also inhabit rocky borders of cypress swamp areas. Much of their population, though, live in twilight zones of caves that are confined to limestone regions. (Camp, et al., 2014; Lanoo, 2005; Petranka, 2010)

  • Aquatic Biomes
  • rivers and streams
  • Other Habitat Features
  • caves

Physical Description

Cave salamanders are among the largest of their genus. During adulthood their dorsal pigmentation ranges from bright reddish-orange to a bland yellow. Their ventral coloring is a light yellow and does not contain spots. Younger adults are typically more dull in color.

The maximum recorded length of an adult is 181 mm. Cave salamanders have broad, flattened heads. Their large eyes measure roughly the same size as their snout length. Snout lengths for females measure to 62 mm on average while males have snouts that measure 60 mm on average. Both sexes have prehensile tails that constitute 52 to 68% of their total length. Cave salamanders have four slender legs, two long forelimbs, and two short hind limbs. Their front legs have four toes and their back legs have five toes that are webbed.

Sexes are distinguished by a number of physical features. Vents on mature males have large margins contoured with papillae. Mature males are also distinguishable by their longer tail compared to those of females. Male mental glands are also more rounded in comparison to females. (Hutchison, 1966; Lanoo, 2005; Petranka, 2010)

  • Sexual Dimorphism
  • sexes shaped differently
  • Range length
    125 to 181 mm
    4.92 to 7.13 in

Development

Cave salamanders go through metamorphosis, although populations of this species may mature at different ages. Metamorphosis can occur as early as 6 months and as late as 18 months of age. Young larvae are active day and night. They switch to a more nocturnal lifestyle as they mature.

Their eggs have been measured up to 5 mm in diameter with white yolk that is 2.4 to 3 mm in diameter. Their eggs have two transparent outer envelopes. The outermost of these 2 envelopes is made up of a peripheral gel, while the inner envelope is filled with fluid. Larvae measure up to 10 mm in length when newly hatched. Hatchlings start off at a mere 9 to 12 mm, but can reach up to 58 mm as they approach adulthood. Young larvae have a broad tail fin. These tail fins start at their hind legs and extend to the tips of their tails. Their skin lacks pigmentation, but contains gray spotting. These spots darken as they mature. As cave salamanders grow, their bodies become brighter or darker in color. They begin colorless and later turn a dull yellow to a bright reddish-orange. (Bishop, 1943; Hutchison, 1966; Lanoo, 2005; Petranka, 2010)

Reproduction

Males pursue female salamanders to initiate courtship. Male cave salamanders court females first by pushing and rubbing the snout of the female. Males then press their cheeks against females and move forward. Females use their cheeks to maintain contact with the backs of males. Males press their pelvic area against the females once they have their tails positioned underneath females. Once this is initiated, they both engage in a tail-straddle walk. During this courtship, chemical communication takes place. Pheromones are known to stimulate the vomeronasal organs of cave salamanders. Pheromones also pass neural information to the hypothalamus. This is a part of the brain responsible for the control of sexual receptivity. Not enough research has been done to know the exact mating systems of cave salamanders. All that is known is that one male courts one female at a time. (Houck and Verrell, 1993; Petranka, 2010)

Females typically lay their eggs deep in caves. They lay 49 to 87 eggs, either singly or clustered, at one time. Little knowledge is known about the reproduction of cave salamanders because of their preference for cave habitats. Eggs are mostly laid in springs underground, streams found in caves, or limestone pools away from cave openings. The number of days until hatching depends temperature. The colder the temperatures, the longer it takes for the eggs to hatch. (Petranka, 2010; Ringia and Lips, 2007)

  • Breeding season
    Cave salamanders breed from October to January.
  • Range number of offspring
    49 to 87
  • Range time to hatching
    10 to 20 days

No parental investment, beyond egg-laying, has been reported for cave salamanders. (Lanoo, 2005)

  • Parental Investment
  • no parental involvement

Lifespan/Longevity

Cave salamanders can in captivity for up to 9.1 years. Their lifespan in the wild is unknown. (Lanoo, 2005; Slavens and Slavens, 1999)

  • Range lifespan
    Status: captivity
    9.1 (high) years
  • Average lifespan
    Status: captivity
    9.1 years
    AnAge

Behavior

Cave salamanders inhabit the twilight zones of caves along with long-tailed salamanders (Eurycea longicauda). This may cause interspecific competition due to their similar diets. Cave salamanders, along with several other amphibians, have a unique ability to use the earth's magnetic field for navigation. They use this sense as a compass to migrate to different locales within caves.

Cave salamanders depend on cave-like conditions to complete stages of their life cycles, such as metamorphosis. These salamanders migrate in the summer to what is known as their summer habitat and home range. They tend to be more active at the surface of the water during summer months. (Hofrichter, 2000; Lanoo, 2005)

Home Range

Active ranges for cave salamanders changes according to the season. However, no areas have been reported for home range. These salamanders do not defend territories. (Lanoo, 2005)

Communication and Perception

Male cave salamanders court females first by pushing and rubbing the snouts of females. It is assumed that mating season occurs during summer and early fall. Cave salamanders communicate using pheromones. Mental glands on their heads assist with transferring pheromones, and Jacobson's organs help them detect chemical signals. Cave salamanders also use the earth's magnetic field to navigate in dark caves. (Houck and Verrell, 1993; Lanoo, 2005; Petranka, 2010)

Food Habits

The diet of cave salamanders consists of small invertebrates. This includes spiders and other small insects. Larvae eat snails, spiders, beetles, and flies. Adults have a more varied diet, hunting prey such as earthworms, ticks, mites, and many other small arthropods. (Petranka, 2010)

  • Animal Foods
  • terrestrial non-insect arthropods

Predation

Cave salamanders may coil their body and wave their tail above their head. This behavior intimidates potential predators. They also have glands throughout their body that produce noxious secretions. There are no recorded predators of cave salamanders. (Lanoo, 2005; Petranka, 2010)

Ecosystem Roles

Cave salamanders commonly carry gastrointestinal parasites. A study showed that 1 or more nematodes were found in 77% of the salamanders tested. The types of parasites found in their gastrointestinal tracts depends on the geographic location in which they live. Parasites that were found include trematodes (Brachycoelium salamandrae) and nematodes (Capillaria inequalis, Oswaldocruzia pipiens, Thelandros magnavulvaris, and Trichoskrjabinia).

Cave salamanders may have interspecific competition with other species of salamander. Often times, cave salamanders will share the twilight zones of caves with other species. (Castle, et al., 2011)

Commensal/Parasitic Species
  • Nematode Trichoskrjabinia sp.
  • Trematodes Brachycoelium salamandrae
  • Nematode Capillaria inequalis
  • Nematode Oswaldocruzia pipiens
  • Nematode Thelandros magnavulvaris

Economic Importance for Humans: Positive

There are no known positive economic impacts of cave salamanders for humans.

Economic Importance for Humans: Negative

There are no known negative economic impacts of cave salamanders for humans.

Conservation Status

Cave salamanders are a species of least concern on the IUCN Red List. They are not listed on any other federal or international list. However, cave salamanders are listed as state-endangered in Kansas, Mississippi, and Ohio. They are also reported as rare in West Virginia. No known conservation actions are currently published for this species. (IUCN SSC Amphibian Specialist Group, 2014; Lanoo, 2005)

Contributors

Sarah Parnell (author), Radford University - Fall 2015, Cari Mcgregor (editor), Radford University, Zeb Pike (editor), Radford University, Karen Powers (editor), Radford University, April Tingle (editor), Radford University, Jacob Vaught (editor), Radford University, Galen Burrell (editor).

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

acoustic

uses sound to communicate

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.

chemical

uses smells or other chemicals to communicate

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.

freshwater

mainly lives in water that is not salty.

magnetic

(as perception channel keyword). This animal has a special ability to detect the Earth's magnetic fields.

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.

migratory

makes seasonal movements between breeding and wintering grounds

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

seasonal breeding

breeding is confined to a particular season

sexual

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

social

associates with others of its species; forms social groups.

tactile

uses touch to communicate

terrestrial

Living on the ground.

visual

uses sight to communicate

References

Bishop, S. 1943. Handbook of Salamanders. Ithaca, New York: Comstock Publishers Assoc. & Cornell University Press.

Briggler, J., J. Prather. 2006. Seasonal use and selection of caves by Plethontid salamanders in karst areas of Arkansas. American Midland Naturalist, 155/1: 136-148.

Camp, C., J. Wooten, J. Jensen, D. Bartek. 2014. Role of temperature in determining relative abundance in cave twilight zones by two species of lungless salamander (family Plethodontidae). Canadian Journal Of Zoology, 92/2: 119-127.

Castle, M., D. Strohlein, B. Christensen. 2011. Helminth Parasites of the Cave Salamander, Eurycea lucifuga, from western Kentucky. Proceedings of the Helminthological Society of Washington, 54/2: 269-270.

Green, D., L. Weir, G. Casper, M. Lannoo. 2013. North American Amphibians Distribution & Diversity. Berkeley and Los Angelas, California: University of California Press.

Hairston, N. 1987. Community Ecology and Salamander Guilds. New York, New York: Cambridge University Press.

Hofrichter, R. 2000. Amphibians: The World of Frogs, Toads, Salamanders and Newts. Buffalo, New York: Firefly Books.

Houck, L., P. Verrell. 1993. Studies of Courtship Behavior in Plethodontid Salamanders: A Review. Herpetologica, 49/2: 175-184.

Hutchison, V. 1966. Catelogue of American Amphibians and Reptiles. Clifton Heights, PA: American Society of Amphibians of Ichthyologists and Herpotologists.

IUCN SSC Amphibian Specialist Group, 2014. "The IUCN Red List of Threatened Species" (On-line). Eurycea lucifuga. Accessed November 06, 2015 at http://www.iucnredlist.org/details/59269/0.

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

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

Ringia, A., K. Lips. 2007. Ovipposition, Early Development and Growth of the Cave Salamader, Eurycea lucifuga: Surface. Herpetologica, 63/3: 258-268.

Slavens, F., K. Slavens. 1999. "Reptiles and Amphibians in Captivity- Breeding, Longevity, and Inventory" (On-line). Accessed November 20, 2015 at http://www.pondturtle.com/welcome.html#INDEX.