** State Endangered **
Eastern Tiger salamander
Amby is Greek for "a cup", stoma is Greek for "a mouth"
tigri is Latin and means "tiger" or "striped like a tiger"
7 - 8.3 in. (18 - 21 cm)
|Virginia Record Length:|
13 in. (33 cm)
Virginia Wildlife Action Plan Rating Tier II - Very High Conservation Need - Has a high risk of extinction or extirpation. Populations of these species are at very low levels, facing real threat(s), or occur within a very limited distribution. Immediate management is needed for stabilization and recovery.
PHYSICAL DESCRIPTION: This is Virginia's largest mole salamander reaching a maximum SVL of 114 mm (4.5 inches) in Virginia and a maximum total length of 254mm. The tail comprises 45% to 51% of the total length. Eastern tiger salamanders appear robust with a broad depressed head and widely separated eyes. The head width is greatest at the corner of the mouth. The tail is compressed throughout most of its length. The general color (in life) is dark brown to dull black background *9286*. This species has olive-yellow or brownish yellow spots or blotches on the back, sides, and belly *1009,9286*. The blotches continue laterally and blend into the olive-yellow venter creating a jagged-edge lateral line. The dorsal markings exist fron the snout to the tail tip. Marking on the tail may appear as bands. Yellow and olive dominate the chin and throat. The venter is yellowish and blotched with darker markings. When preserved, the colors fade, leaving a brown mottled salamander dorsally and a venter that is light brown to cream with brown to grey spots or mottling. There is no sexual dimorphism in body size but the male have a longer tail. When breeding, the area surrounding the male's vent is swollen while the female is much less so. Gravid females are more plump than males or non-gravid females. The hatchlings average 12.5 mm total length. The dorsum is more pale than other ambystomatids and the venter is characteristically pale yellow to white which is evident from hatching. A prominent gular fold is present. The muscular portion of the tail is dark with indistinct mottling. There is a dorsolateral row of light spots of one spot per costal fold. The tail is broad and compressed laterally. The larvae are pond type, lacking balancers, but with large gills. The head is broad and bluntly rounded. Larvae differ from other Virginia Ambystomatids in the paler coloration and lack of balancers. The toes are uniquely depressed and pointed *9286*. The length is up to 254 mm. This is the largest species of Ambystoma *1009*.
REPRODUCTION: The breeding migration is between January and March, and the males arrive first usually outnumbering females *2929*. This species breeds from December to February *972*. Mating activities reach a peak during rain, and the adults remain in the breeding pond for about 3 weeks *2930*. The eggs average 52 per mass and vary from 23-110 *1009*. The incubation period is 30-40 days *1009*. Egg deposition not synchronous. The eggs are probably deposited in 5-8 masses *915*. The entire egg mass may turn green which is caused by a green algae, chlamydomonas, that grows in the jelly-like mass creating a symbiotic relationship *2929*. The eggs hatch in 30 days *2930*, and breeding occurs in temporary ponds where water is limited *915*. The egg mass is fastened to plant twigs and stems in shallow ponds *865*.
BEHAVIOR: The adults are terrestrial most of the year and reside in mammal burrows *2932,2933*. They are also nocturnal and fossorial and inhabit any type of woodland or marshy grassland *865*. This species selects damp substrates and remains in burrows or under surface cover possibly to reduce cutaneous water loss *2934*. It selects or is restricted to moist, humid microhabitats to avoid dessication *2935* and spends most of its life below ground *2934*. This species exhibits vertical migration and nocturnal stratification *2936*. The larvae transform in the summer after 2-4 months *915*. It is preyed upon by Ambystoma opacum larvae. They are opportunistic feeders *2929*. Breeding waters are found in semidesert regions, pine barrens, and forests of plains and mountains *1009*. The larvae hide in vegetation or bottom debris in ponds where they are hatched, as do the aquatic juveniles *915*. They may inhabit crayfish burrows *1008*. This species breeds in ponds, bogs, or marshes *949*. They are not territorial and forage on the ground and in the water.
ORIGIN: This species is native *1009*. This species is know to be able to dig its own burrows. The larvae feed on insects, crustaceans, amphibian larvae, and mollusks. The adults feed on almost anything they can capture and are ravenous feeders in captivity *9286*. Limiting factors: A threat exists for genetic contamination in Virginia with an increased popularity in ambystomatid larvae as fish bait. A single male was was found to move approximately 175 meters from the breeding pond during the non breeding season *9286*. Aquatic/terrestrial associations: Aquatic associations include Ambystoma opacum and Chrysemys picta. Terrestrial associations include A. maculatum, Notophthalmus v. viridescens and Bufo americanus *915,949,1008,865*. Notophthalmus viridescens feed on eggs and small larvae of this species *9286*.
References for Life History
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