Description
Ambystoma mabeei is a short, stout salamander with a short snout that is round and blunt (Bishop 1928). Most specimens have a snout-vent length of approximately 100 mm. The head is small and narrower than the body, and the tail is relatively short; the tail length is approximately 40% of the body length (Hardy and Anderson 1970). Most specimens have 13 costal grooves and two intercostal spaces between the adpressed limbs. The tail is thick and covered with gland cells, and there are nine vertical, linear indentations on the tail. There are inconspicuous median dorsal and ventral lines that extend from above the forelegs to the vent. Ambystoma mabeei has a smooth dorsal surface, and it can be identified by its long toes (Conant and Collins 1998). Individuals have four toes per hand and five toes per foot, and poorly-developed tubercles are present on both the hands and feet. Ambystoma mabeei has a well-developed gular fold (Bishop 1928).

Ambystoma mabeei is morphologically similar to the Plethodon glutinosus complex, Ambystoma cingulatum, A. jeffersonianum, A. opacum, A. maculatum, and A. talpoideum (Bishop 1928, Conant and Collins 1998). Ambystoma mabeei can be differentiated from the Plethodon glutinosus complex as members of the species complex have a groove from their nostril to their lip that is absent in A. mabeei. While A. mabeei only has distinct spots along its sides, A. cingulatum has a speckled pattern all over its head and body. Ambystoma mabeei and A. jeffersonianum have non-overlapping ranges, with A. mabeei found in the coastal regions between Virginia and South Carolina, while A. jeffersonianum is generally found north of Virgina and further inland (Conant and Collins 1998). While A. mabeei has similar proportions to A. opacum, the marbled coloring of A. opacum is very different, light vs. grey to greyish-brown respectively (Bishop 1928, Conant and Collins 1998). Additionally, A. opacum only has 11 or 12 costal grooves while A. mabeei has 13. Lastly, A. opacum’s tongue has a visible median groove, whereas A. mabeei does not, and a different size and shape of its head (Bishop 1928). The patterning and color of A. mabeei is significantly different from A. maculatum with the former having light speckles and the latter having yellow to orange spots. Ambystoma mabeei has a distinctly small head and long toes that differentiates it from A. talpoideum, which has a large head (Conant and Collins 1998). Ambystoma mabeei is a member of the subgenus Linguaelapsus, which includes A. annulatum, A. barbouri, A. cingulatum, A. mabeei and A. texanum. They share similarities in their skulls and hyobranchial skeletons, but they differ in their colorations and proportions (Shaffer et al. 1991). Additionally, Ambystoma mabeei has non-overlapping ranges with A. annulatum and A. barbouri, which are both found much further west and inland (Conant and Collins 1998). Although A. mabeei resembles Ambystoma texanum, they have a consistently different number of costal grooves, dissimilar body shapes and proportions, and mismatched numbers and arrangements of teeth (Bishop 1928).

In life, Ambystoma mabeei is the dorsal background color is deep brown to black and the ventrum is gray or dark brown. There are light specks along the entire body, but they are the lightest and most visible along the sides of the body (Conant and Collins 1998).

In preservation, A. mabeei is a uniform medium gray with a slightly lighter ventral surface (Bishop 1928).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: United States

U.S. state distribution from AmphibiaWeb's database: North Carolina, South Carolina, Virginia

	View distribution map in BerkeleyMapper.
	View Bd and Bsal data (1 records).

Ambystoma mabeei is only found in the United States, specifically along the coasts of North Carolina, South Carolina, and Virginia. Ambystoma mabeei lives mostly in lowland forests, inland and seasonal wetlands, and at the bottoms of tupelo and cypress trees (McCoy and Savitsky 2004).

Life History, Abundance, Activity, and Special Behaviors
Ambystoma mabeei begins their breeding period in mid-January, and it continues until the end of March. Breeding occurs in ponds, which vary greatly in size and can have pH values as low as 4.5 (McCoy and Savitsky 2004). According to observations in their habitats, the courtship of A. mabeei occurs during late winter or early spring, when it rains the most (Hardy and Anderson 1969).

Eggs are laid one-by-one or in short connected strings. Once laid, they are attached to the leaves, twigs, or roots of plants near the ponds. The eggs are 5.1 to 5.9 mm in diameter, and larvae hatch after 9 to 14 days. Once transformed, the adults may move far from their breeding ponds, typically during heavy rains (Hardy and Anderson 1969).

Adult A. mabeei uses passive anti-predator mechanisms, including weak tail lashing and retracting limbs while assuming an immobile position (Lannoo 2005).

Larva
Larvae are yellow and brown on the dorsal side and flesh-colored on the ventral side. The larvae have a light mid-dorsal stripe and three dark lateral stripes, one of which has one row of inconspicuous dots. In some older larvae, dark mottling is expressed along their fins (Hardy and Anderson 1970).

At the time of hatching, larvae are approximately 8.5 mm long, and they begin to metamorphose at 50 mm (Hardy and Anderson 1970).

Ambystoma mabeei larvae are considered generalist predators, as they have a varied diet; they eat isopods, copepods, amphipods, ostracods, cladocerans, insects, and the larvae of other amphibians. In addition, they have been known to eat algae, plant seeds, and snails. Larvae may eat larger insects, such as mayflies, as they grow and their energy demands increase (McCoy and Savitsky 2004).

Larval Ambystoma mabeei may have avian predators, which leads them to hide in leaf litter as they develop. Additionally, larvae are prone to parasitic nematodes in their digestive systems, especially in the specimens collected from North and South Carolina (McCoy and Savitsky 2004). Lesser sirens and the larvae of tiger salamanders are predators of A. mabeei (Lannoo 2005).

Trends and Threats
While Ambystoma mabeei has a stable population on a national scope, the Commonwealth of Virginia has classified A. mabeei as a "Threatened" species. Changes in agriculture and deforestation are threatening their habitats and have the capacity to decrease the populations of A. mabeei. Conservation areas have been identified over the entire range of A. mabeei’s population, and its stability can be preserved through proper natural resource management and habitat restoration (Hammerson and Mitchell 2004).

Possible reasons for amphibian decline

General habitat alteration and loss
Habitat modification from deforestation, or logging related activities
Intensified agriculture or grazing

Comments
Bishop (1928) used morphological characteristics to hypothesize that A. mabeei is related to the group containing A. jeffersonianum, A. opacum, and A. maculatum. However, more recent research has shown that A. mabeei is actually related to the clade containing Ambystoma annulatum, Ambystoma barbouri, Ambystoma cingulatum, and Ambystoma texanum. This grouping, which has since been classified as the subgenus Linguaelapsus, is strongly supported by a combination of molecular data analysis -- utilizing allozymic and molecular DNA analysis -- and morphological traits, like their skulls and hyobranchial skeletons (Shaffer et al. 1991).

The species name, “mabeei,” comes from W.B. Mabee, the first person to collect an Ambystoma mabeei specimen (Bishop 1928).

References

Bishop, Sherman C. (1928). ''Notes on some amphibians and reptiles from the southeastern states, with a description of a new salamander from North Carolina.'' Journal of the Elisha Mitchell Scientific Society, 23(3/4), 153-170.

Conant, R. and Collins, J.T. (1998). A Field Guide to Reptiles and Amphibians of Eastern and Central North America. 3rd Edition. Houghton Mifflin Company, Boston, Massachusetts.

Hammerson, G., Mitchell, J. 2004. ''Ambystoma mabeei''. The IUCN Red List of Threatened Species: e.T59062A11864333. https://dx.doi.org/10.2305/IUCN.UK.2004.RLTS.T59062A11864333.en.

Hardy, J. D., Jr., Anderson, J. D. (1970). ''Ambystoma mabeei.'' Catalogue of American Amphibians and Reptiles, 81, 1-2.

Lannoo, M. J. (2005). Amphibian Declines: The Conservation Status of United States Species. University of California Press, Berkeley.

Mccoy, M., Savitzky, A. (2004). ''Feeding ecology of larval Ambystoma mabeei (Urodela: Ambystomatidae).'' Southeastern Naturalist, 3, 409-416.

Shaffer, H. B., Clark, J. M., Kraus, F. (1991). ''When molecules and morphology clash: A phylogenetic analysis of the North American ambystomatid salamanders (Caudata: Ambystomatidae).'' Systematic Zoology, 40, 284-303.

Species Account Citation: AmphibiaWeb 2023 Ambystoma mabeei: Mabee's Salamander <https://amphibiaweb.org/species/3839> University of California, Berkeley, CA, USA. Accessed Nov 27, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 27 Nov 2024.

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