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.
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.
- Habitat Regions
- temperate
- terrestrial
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.
- Other Physical Features
- ectothermic
- heterothermic
- bilateral symmetry
- Sexual Dimorphism
- female larger
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.
- Development - Life Cycle
- metamorphosis
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.
- Mating System
- monogamous
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.
- Key Reproductive Features
- iteroparous
- seasonal breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- sexual
- fertilization
- oviparous
Male pygmy salamanders do not play any role in helping with their young. However,
females tend to eggs and to newly hatched salamanders.
- Parental Investment
- female parental care
-
pre-fertilization
- provisioning
-
protecting
- male
-
pre-hatching/birth
-
provisioning
- female
-
protecting
- female
-
provisioning
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.
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.
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.
- Other Communication Modes
- pheromones
- scent marks
Food Habits
Pygmy salamanders primarily feed at night on small arthropods in the soil and leaf
litter.
- Primary Diet
-
carnivore
- insectivore
- eats non-insect arthropods
- 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.
- 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.
- leech ( Oligobdella biannulata )
- trypanosomes ( Trypanosoma )
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.
- 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.
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.
Additional Links
Contributors
Cecilia de la Garza (author), Radford University, Karen Powers (editor), Radford University, Tanya Dewey (editor), University of Michigan-Ann Arbor.
- 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.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- 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.
- forest
-
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
- mountains
-
This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.
- ectothermic
-
animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature
- 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.
- 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.
- monogamous
-
Having one mate at a time.
- 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).
- 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
- fertilization
-
union of egg and spermatozoan
- internal fertilization
-
fertilization takes place within the female's body
- oviparous
-
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
- female parental care
-
parental care is carried out by females
- nocturnal
-
active during the night
- motile
-
having the capacity to move from one place to another.
- sedentary
-
remains in the same area
- solitary
-
lives alone
- tactile
-
uses touch to communicate
- chemical
-
uses smells or other chemicals to communicate
- 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
- visual
-
uses sight to communicate
- tactile
-
uses touch to communicate
- 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.
- carnivore
-
an animal that mainly eats meat
- insectivore
-
An animal that eats mainly insects or spiders.
- 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.
References
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Goater, T. 2000. The Leech, Oligobdella Biannulata (Glossiphoniidae) on Desmognathine Salamanders: Potential for Trypanosome Transmission?. American Midland Naturalist : 434-438.
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