Ambystoma annulatumRinged Salamander

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Geographic Range

Ambystoma annulatum has been mostly found in the vicinity of Hot Springs Arkansas and throughout most of the forested Ozark Plateau in Missouri (Bishop 1962, Johnson 1977). Small populations of ringed salamanders have been found in south western Illinois and eastern Oklahoma as well (Petranka 1998). (Bishop, 1962; Johnson, 1977; Petranka, 1998)

Habitat

Ambystoma annulatum prefers damp hardwood forests that are near shallow ponds (Bishop 1962). These salamanders are usually found hidden under rocks and logs, in piles of dead leaves, or burrowing in the soil; most of the year is spent below the surface of the ground (Bishop 1962, Johnson 1977). (Bishop, 1962; Johnson, 1977)

  • Aquatic Biomes
  • lakes and ponds
  • temporary pools

Physical Description

Adult ringed salamanders range in length from 140 to 180 mm (5 1/2 to 7 inches). The record length is 255 mm (9 1/2 inches). Ambystoma annulatum has a slender well-rounded body with a small elongated head and a long tail. They have depressed snouts that are evenly and bluntly rounded. A. annulatum has about 15 costal grooves and 5 toes on the hind feet. They also have "vomerine teeth in two short series entirely between the inner nares, each series consisting of three rows of about 7 - 11 small blunt teeth" (Bishop 1962).

This is a striking salamander that is a dark blackish brown color with light cross bands and spots that are a buff - yellow color. There is some variation in the intensity of the markings. The belly is a pale grayish white. Usually, there is a short, light colored bar between the eyes. Someimes this continues below the eyes, pointing backwards diagnally. Looking from the top, the tail and body can appear to be completely ringed, hence the name "ringed" salamander. Interestingly enough, the rings never completely go around the body. Males and females are monomorphic and no textual evidence has been found if geographic or seasonal variation within the species exists.

The larvae of ringed salamanders are an average of 48 mm in length. They have well developed legs and toes and have a dorsal fin that extends to the head. Dorsally and on the lower sides there is uniform coloration. On the sides there is a broad, definite band lacking pigmentation from the gills to two-thirds down the tail. Juveniles get their yellow coloration after metamorphosis, and form their adult patterns within two months

(Bishop 1962, Johnson 1977, Petranka 1998).

  • Sexual Dimorphism
  • sexes alike
  • Range length
    140 to 255 mm
    5.51 to 10.04 in

Development

Reproduction

Eggs are fertilized internally via spermatophores and the eggs are deposited in shallow, fishless water in the fall, mostly in October (Petranka 1998). Courtship occurs in shallow water as well (Johnson 1977).

They reproduce at night in breeding ponds where hundreds of them congregate. Usually the males are found at the breeding ponds first, and are distinguishable from the females by their swollen cloacas (Bishop 1962). Males will usually approach females. They start off by nudging the female's cloaca, and then swim off a short distance and deposit a few spermatophores (Petranka 1998). A male may deposit nine spermataphores in two minutes (Petranka 1998). The more males that come into the breeding area, the less specific males get when depositing spermatophores, nudging both males and females before deposition (Petranka 1998). Males deposit spermatophores on rocks, on other spermatophores, and even on other individuals. At this time females are generally passive and do not pick up seminal fluid while they are actively being courted by males (Petranka 1998). Breeding lasts a few days, after which the salamanders begin to move away from the ponds (Bishop 1962). (Bishop, 1962; Johnson, 1977; Petranka, 1998)

Ringed salamanders reproduce in shallow water. Breeding takes place in the fall between September and November (Bishop 1962). Cool temperatures and heavy rains stimulate breeding. Females begin ovipositing within 1 - 2 days after breeding. These salamanders are usually sexually mature 2 - 3 years after metamorphosis (Petranka 1998). Eggs are laid in clusters with an average of 10 eggs in a cluster (Bishop 1962). Usually, about 150 eggs are laid in total and are sometimes attached to vegetation but are usually laid directly on the bottom of ponds (Bishop 1962). The embryonic period of A. annulatum is fairly short. Premature pond freezing and drying are the biggest risks to the embryos and larvae (Petranka 1998). A. annulatum is an explosive breeder, and at times breeding males will try to reproduce 2 - 4 times during the breeding season (Petranka 1998). (Bishop, 1962; Petranka, 1998)

  • Breeding interval
    Breeding occurs once yearly.
  • Breeding season
    Breeding occurs during the fall, between September and November.
  • Average number of offspring
    150
  • Range age at sexual or reproductive maturity (female)
    2 to 3 years
  • Range age at sexual or reproductive maturity (male)
    2 to 3 years

Aside from provisioning eggs before fertilization there is no parental care.

  • Parental Investment
  • no parental involvement

Lifespan/Longevity

Longevity in ringed salamanders is unknown. Some other salamander species may live up to 10 years.

Behavior

Ringed salamanders are solitary except during the breeding season. They are most active during moist weather and spend most of their time underground or under leaf litter.

Communication and Perception

Ringed salamanders may communicate mainly through chemical and tactile cues during the breeding season.

Food Habits

Ambystoma annulatum is carnivorous, eating mostly earthworms, insects, land snails, and other invertebrates (Johnson 1977). Cannibalism has been observed in this species in both the field and the laboratory (Petranka 1998). Larvae of A. annulatum eat ostracods, hemipterans, and dragonfly and damselfly nymphs (Petranka 1998). (Johnson, 1977; Petranka, 1998)

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

Predation

Predators of ringed salamanders include owls, snakes, shrews, skunks, raccoons, opossums, and other mammals (Petranka 1998). When these salamanders are being attacked or feel threatened they will coil their bodies while tucking their heads underneath the base of their tales for protection (Petranka 1998). (Petranka, 1998)

Ecosystem Roles

Ringed salamanders are important predators of small invertebrates in the ecosystems in which they live. Some animals may depend on the dense aggregations of salamander eggs during the breeding season.

Economic Importance for Humans: Positive

Ringed salamanders are not economically important to humans, but are of interest to scientists and to nature-oriented tourists. It is a specialized species, unique to its Ozark habitat. Because of their docility and striking appearance, they might be useful in environmental education programs (Petranka 1998). (Petranka, 1998)

Economic Importance for Humans: Negative

There are no negative impacts of ringed salamanders.

Conservation Status

Ringed salamanders are an increasingly rare (and probably endangered) animal, most likely because of their restricted range and specific breeding requirements (Petranka 1998). The breeding habitats for these creatures should be protected whenever possible. (Petranka, 1998)

Contributors

Leslie Seaholm (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.

carnivore

an animal that mainly eats meat

chemical

uses smells or other chemicals to communicate

ecotourism

humans benefit economically by promoting tourism that focuses on the appreciation of natural areas or animals. Ecotourism implies that there are existing programs that profit from the appreciation of natural areas or animals.

ectothermic

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

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.

fossorial

Referring to a burrowing life-style or behavior, specialized for digging or burrowing.

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.

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.

oviparous

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

polygynous

having more than one female as a mate at one time

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

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

Bishop, S. 1962. Handbook of Salamanders. New York: Hafner Publishing Company.

Johnson, T. 1987. The Amphibians and Reptiles of Missouri. Missouri Department of Conservation.

Johnson, T. 1977. The Amphibians of Missouri. Lawrence: University of Kansas Publications.

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