Getting to Know Vernal Pool organisms - Jefferson Salamander
Getting to Know Vernal Pool organisms - Jefferson Salamander
Grade Levels
Course, Subject
Organism Name
Photo by Solon Morse.
Common Name: Jefferson Salamander
Scientific Name: Ambystoma jeffersonianum
Classification Information
Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Amphibia
Order: Caudata
Family: Ambystomatidae
Genus: Ambystoma
Species: Ambystoma jeffersonianum
Geographic Range and Habitat
Geographic Range: The Jefferson salamander is distributed in patches from southern New England, south and southwest through Indiana, Kentucky, West Virginia, and Virginia.
Habitat: The Jefferson salamander is restricted to sites containing suitable breeding ponds and shows a strong affinity for upland forests. It prefers relatively undisturbed deciduous woodlands, especially moist, well-drained upland forests.
Physical Characteristics
Physical Description: The Jefferson salamander can vary from a dark brown, brownish gray or slate gray dorsum and may have light blue speckles scattered along the sides, tail, and occasionally extending onto the back. The speckling is most apparent in younger individuals and may disappear in older adults. The vent region is a grayish color and the ventrum is a pale, sometimes silvery, color. Ambystomid salamanders are generally characterized by prominent costal grooves, short, rounded heads, and stout bodies with robust limbs. The Jefferson salamander, however, has relatively long, slender limbs and toes comparatively. The tail is laterally compressed and extends almost as long as the body. The average adult length ranges from 10.7 to 21 cm, with females being in the upper part of the range, and 12 to 14 costal grooves are present. Breeding males have swollen vents and appear more slender than the egg carrying females. The tail is also longer and more laterally compressed in males. Outside of the breeding season both sexes are darker and less conspicuously marked. Larvae are a yellowish green color with dark blotches on the back. They possess a relatively uncolored caudal fin, and display external gills upon hatching. Older larvae have a mottled greenish gray dorsum and may be marked along the sides with small yellowish spots while the ventrum is pale and generally unmarked.
Diet

Diet:
The Jefferson salamander generally feeds on insects and other invertebrate species. The larvae are found to consume small zooplankton after hatching and move on to organisms such as nematodes, aquatic insect larvae, insects, and snails. Larvae may become cannibalistic and feed on small larvae of their own kind and others. Because the adult salamanders spend most of the time, outside of the breeding season, hidden in the ground or under leaf litter their exact feeding habits are not known. It is presumed that they feed on earthworms and other invertebrates found in the soil.

Reproduction
Reproduction: The Jefferson salamander is one of the earliest seasonal breeders, migrating to breeding ponds in late winter or early spring, often before the ground and ponds are completely thawed. The first group of males typically precedes the arrival of the first females. Current data suggest that while males breed annually, females may skip one or more years before breeding again. Salamanders are unique among amphibians in practicing internal fertilization. During courtship, the male deposits a spermatophore, a packet of sperm that the female picks up with the lips of her cloaca. The spermatophore is then stored in her spermatheca until she is ready to lay her eggs. While there is no direct cloacal contact, fertilization is internal.
Eggs: Females may begin to lay eggs one to two days after mating. The eggs are 2-2.5 mm in diameter and are encircled by a vitelline membrane and three jelly envelopes. They are generally deposited in small gelatinous clusters and are attached to underwater sticks or vegetation. If the pond should freeze, the eggs are then protected below the surface of the water. The egg masses generally vary in numbers of 20 to 30 eggs per mass but may have anywhere between 1 and 60 eggs per mass. Females will produce a total of 100 to 280 eggs in one breeding season. The length of the incubation varies. In a controlled setting with temperatures around 21oC eggs will hatch in about two weeks, but under more typical, natural conditions, may take up to 14 weeks depending on the time the eggs were laid. The average embryonic survival to hatching is observed to be positively correlated with egg mass size.
Larvae: Hatching success can be very high, however, larvae survival rate is generally very low due to predation. The newly hatched larvae range in length from 1.0 to 1.4 cm. In two to three months the surviving larvae metamorphosied into terrestrial salamanders. If the breeding pond threatens to prematurely dry up, metamorphosis will occur sooner with smaller larvae. The newly metamorphosized individuals range from 4.8 to 7.5 cm and are able to breed in two to three years. The average life span of the Jefferson salamander is six years or longer.
The Jefferson Salamander is an Obligate Species and must live or breed in vernal pools.
Natural History
Natural History: One of the most interesting aspects of salamander behavior collectively is their stubbornness to move from an area. Salamanders are generally not very active and in its entire lifetime may not travel more than a mile. It is estimated that approximately fifty percent of all salamanders die during hibernation because they will remain in areas that are too cold for them rather than moving to a more suitable place.
Various defensive behaviors have been observed when this species is confronted by a predator. Its predators include owls, snakes, striped skunks, and raccoons. Behavioral and defensive responses to these predators include a variety of tail movements and body posturing, fleeing, biting, and the production of noxious secretions from skin glands concentrated on the upper base of the tail. Expanding on the observed body movements, this salamander has been noted to raise the tail and undulate or lash it about. The salamander may also tuck its head under its tail forming a coil or engage in body flipping. The jefferson salamander is also capable of voluntarily shedding its tail when threatened. Muscle contractions in the detached tail cause it to twitch violently in hopes of diverting the predator so the salamander has a chance to escape. The superior regenerative powers of salamanders allow for this defense to be effective with minimal consequences to the salamander itself.
Conservation
Vernal Pool Conservation
What you can do:
- Resist the temptation to clean up in and around vernal pool habitats. Leave trees, bushes, and understory vegetation, as well as brush, logs, and dead trees.
- Leave a buffer of natural vegetation around the pool for as great a distance as possible back from the edge of the pool's high-water mark. A buffer of at least 100 feet will help maintain water quality, but will do little to protect amphibians living around the pool. Vernal pool breeders require at least 300 yards of natural habitat around their pools in order to survive.
- Do not fill in the pool, even when it is dry, by dumping leaves or other debris in it.
- In areas with more than one pool, try to maintain travel corridors of natural vegetation between them. If some clearing is necessary, avoid drastic alterations that remove most of the trees and other cover. If habitat alterations are necessary, conduct these activities between November and March, when amphibians are less likely to be present. Activities done when the ground is frozen will cause much less damage to the soil than those conducted during warmer months.
- Avoid activities that inadvertently alter the movement of surface water (hydrology) of the upland area that drains into the pool. Digging ditches and similar activities can change runoff into the pool, thereby altering its flooding cycle.
- Do not dig into the bottom of the pool, even when it is dry, as this will disturb the non-permeable layer of soil that allows the pool to flood.
- Work with local conservation commissions and other interested individuals to identify and document vernal pools in your area.
*Adapted from the Audubon Society of New Hampshire and the Nongame and Endangered Wildlife Program of the New Hampshire Fish and Game Department.
Did You Know?
Photo by Tom Lautzenheiser.
A vernal pool is a temporary or semi-permanent body of water, typically filled in the spring by snow melt and spring rain, and holding water for two or three months in the spring and summer.
Vernal pools form in contained basin depressions, meaning that while they may have an inlet, they have no permanent outlet forming a downstream connection to other aquatic systems. They are typically small, rarely exceeding 50 m in width, and are usually shallow. While most are filled with meltwater and spring rains, others may be filled during the fall or with a combination of seasonal surface runoff and intersection with seasonally high groundwater tables. Typical substrates are formed primarily of dense leaf litter. While most vernal pools are found in upland forest, several types have been identified, including floodplain basins, swamp pools and marsh pools.
Periodic drying is a key feature of the ecology of vernal pools. Drying precludes the establishment of permanent fish populations, which would otherwise act as predators on the eggs and larvae of species that live or breed in the pool. While a typical vernal pool is dry during at least part of the year, others may contain some water throughout the year (or for several years), but a combination of shallow water, summer heat, winter freezing, and periodic oxygen depletion prevent the establishment of fish populations.
Additional Information
Terms:
Obligate Species: Species must live or breed in vernal pools.
Faculative Species: Species may be found in vernal pools, but can reproduce in other aquatic habitats where they are available.
Acanthal ridges: Ridges (with light lines) extending from the eyes to the nostrils in spring salamanders.
Costal grooves: The grooves present along the sides of the bodies of many salamanders. When counting them for identification purposes, include only those between the front legs and the hind legs.
Keeled tail: A salamander tail that narrows to a knife edge along its dorsal (top) surface.
Nasolabial grooves: Narrow grooves that extend from the nostrils to the mouth in salamanders of the family Plethodontidae.
Portions Adapted From
Kipp, S. 2000. "Ambystoma jeffersonianum" (On-line), Animal Diversity Web
Accessed March 30, 2004 at https://animaldiversity.ummz.umich.edu/site/accounts/information/Ambystoma_jeffersonianum.html
Description
The Roger Tory Peterson Institute is a national, non-profit nature education organization with headquarters in Jamestown, New York, birthplace of world renowned artist and naturalist, Roger Tory Peterson (1908-1996). In collaboration with the Center for Applied Technologies in Education, the Roger Tory Peterson Institute has provided these animal profiles to offer a glimpse into the diversity of Vernal Pools in our region.