Geographic Range
Southern two-lined salamanders have a Nearctic distribution. They are found in the
eastern and southeastern United States. Southern two-lined salamanders occur from
central Indiana and Ohio east to coastal Virginia and south through Kentucky, Tennessee,
and Georgia to north Florida and coastal Alabama, Mississippi and Louisiana, west
to the Mississippi River. They are replaced in the Smoky Mountains by
Eurycea wilderae
and in the northeastern United States and southern Canada by
Eurycea bislineata
, with which it was recently considered conspecific (Jacobs 1987). Some authorities
consider these three forms as subspecies of
Eurycea bislineata
.
Habitat
Southern two-lined salamanders can be found in moist environments, such as creek or
river swamps, seepages, and hardwood forests, often hiding underneath leaf litter,
vegetation, or logs, and in aquatic habitats where fish are absent or rare. During
wet weather,
Eurycea cirrigera
will often emerge from hiding and move about on the surface in moist woodlands. Southern
two-lined salamanders are most abundant in mountainous regions.
- Habitat Regions
- temperate
- terrestrial
- freshwater
- Aquatic Biomes
- lakes and ponds
- rivers and streams
- Other Habitat Features
- riparian
Physical Description
Southern two-lined salamanders are small salamanders, reaching only about 6 to 12 cm total length as adults. Similar to northern two-lined salamanders , however Eurycea cirrigera has 14 costal grooves rather than 15 or 16. The body is yellow orange to rusted color and there are two dark-brown stripes running the length of its body, breaking off into a speckled pattern towards the tail. The back and often the sides are speckled with similar colored dark-brown spots. The tail is fairly long, comprising nearly 50% of its total length.
The name
Eurycea cirrigera
is derived from the two cirri that grow on males during breeding season. Cirri are
small, antennae-like lobes hanging from the salamander's snout. It is thought these
cirri are connected with the nasolabial grooves and vomeronasal organ and sensing
system and are presumably important for recognizing females and competing males.
- Other Physical Features
- ectothermic
- heterothermic
- bilateral symmetry
- Sexual Dimorphism
- female larger
- sexes shaped differently
- ornamentation
Development
Eggs take about 4 to 10 weeks to hatch, depending on water temperature. Emergence
of larvae can be as early as January in the south to May or June farther north. Upon
emergence from the egg clutch, larval
Eurycea cirrigera
are completely aquatic. They are "stream-type" larvae and have reddish colored external
gills, are mostly "dusky" gray above, with six to nine pairs of light spots on the
sides, and have a large tail fin. Primary food for larvae is taken at the same trophic
level as the adults, consisting of copepods, isopods, and chironomids (Pauley and
Watson 2009).
When larvae are beginning to undergo metamorphosis into the adult form, the characteristic
yellowish belly begins to form and the tail fin and gills begin to recede.
True adulthood is determined by length rather than age. Generally it takes between
1 and 3 years for
Eurycea cirrigera
to develop all the key features of an adult; shorter maturation periods occur in
the southern part of the range (Jakubanis, Dreslik, and Phillips 2008).
- Development - Life Cycle
- metamorphosis
Reproduction
Depending on local conditions, mating can occur from September through May. Mating
can occur in water or on land. Courtship involves nudging and "sniffing" behaviors
by the male, and he may use his premaxillary teeth to scratch the female's skin, probably
to introduce pheromone secretions from his mental gland (on the chin) into the female's
bloodstream. This is eventually followed by the female straddling the male's tail
as they walk forward. Fertilization involves the male depositing a spermatophore,
which the female picks up with her cloaca; thus fertilization is internal.
- Mating System
- polygynandrous (promiscuous)
Males grow 2 cirri below their snout during mating season, it is expected that this
is to sense both mates and competition (Distler et al., 1998) Eggs are deposited from
the end of March until May, depending on location. Females generally lay their eggs
under rocks, logs, or other shelter, always underwater in a stream or river. Eggs
are never laid on terrestrial areas. They generally number from 15 to nearly 100 per
nest (Pauley and Watson, 2009; Petranka, 1998). Females guard their nests until the
eggs hatch.
- Key Reproductive Features
- iteroparous
- seasonal breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- sexual
- oviparous
Females must develop and yolk eggs, expend energy during courtship, and then stay
with the eggs until hatching. Males expend much energy during courtship and in defending
terrestrial territories.
- Parental Investment
-
pre-fertilization
- provisioning
-
protecting
- female
-
pre-hatching/birth
-
provisioning
- female
-
protecting
- female
-
provisioning
Lifespan/Longevity
Little is known about the maximum or potential lifespan of this salamander in the
wild. Related species in this genus are known to have lived over 9 years in captivity.
Behavior
Southern two-lined salamanders are cryptic, spending most of their time under logs
or foliage hiding from their many predators. On damp nights they may emerge and forage
on the forest floor.
In the presence of other males, they are known to be territorial. A territorial male
will approach the intruding male, and bump the intruder in with its snout. Occasionally,
the defending male will even snap at the intruder, potentially removing its tail (Grant
1955).
These salamanders may hibernate in winter, however movement and feeding during winter
months has been noted and the extent of dormancy is undoubtedly related to local and
regional conditions. When they hibernate they burrow 20 to 30 cm into the soil (Vernberg
1953). Feeding may occur throughout the year if conditions are suitable.
- Key Behaviors
- terricolous
- fossorial
- natatorial
- diurnal
- nocturnal
- motile
- sedentary
- hibernation
- solitary
- territorial
Home Range
In laboratory settings, a typical movement range of
Eurycea cirrigera
is between 5 and 6 inches (12.7 to 15.2 cm) from a resting area. In the wild, these
salamanders may make seasonal migrations between streams and terrestrial woodland
habitat of up to 10 m.
Communication and Perception
Communication during courtship and territorial encounters is largely tactile and through
detection of chemicals (pheromones). Visual signals in the form of posturing are also
used.
- Other Communication Modes
- pheromones
- scent marks
Food Habits
Southern two-lined salamanders are opportunistic predators, eating whatever small
organisms they encounter, both as aquatic adults and terrestrial adults. This includes
crustaceans
,
mollusks
,
copepods
, and
insects
. Though their larvae are known to eat other species of salamander larvae, it was
recently found that their larval diet primarily consists of
chironomids
, or midges, which are available year round, in both good and poor water conditions.
Petranka (1998) listed the diet of adults as including
roaches
,
spiders
,
ticks
,
earthworms
,
isopods
,
millipedes
,
beetles
,
snails
,
springtails
,
flies
, and
hymenopterans
.
- Primary Diet
-
carnivore
- insectivore
- eats non-insect arthropods
- molluscivore
- vermivore
- Animal Foods
- amphibians
- insects
- terrestrial non-insect arthropods
- mollusks
- terrestrial worms
Predation
Predators of southern two-lined salamanders include birds, such as thrushes and screech
owls, fish (rainbow trout and brook trout), garter and ring-necked snakes, crayfish
(in larval stages), and other salamanders (Pauley and Watson 2009). In the presence
of black-bellied salamanders (
Desmognathus quadramaculatus
), southern two-lined salamanders were found to migrate further from stream to drier
sites, indicating that this larger species could be a recognized predator (Grover
2000).
Eurycea
larvae restrict their movements and remain hidden more in the presence of larger
larvae in the genus
Gyrinophilus
. When they are in the presence of garter snakes, adult salamanders are known to use
a protean flipping escape, followed by running away (Ducey and Brodie 1983). They
will readily autotomize (drop) their tails when attacked by snakes and other predators.
- Anti-predator Adaptations
- cryptic
Ecosystem Roles
Small
plethodontid
salamanders have been shown to play a significant part in cycling nutrients between
the forest leaf litter community and larger vertebrates, as they can build up large
populations and and represent large portions of biomass. Research done on
northern two-lined salamanders
is undoubtedly relevant to southern two-lined salamanders as well (Burton and Lichens
1975).
- Ecosystem Impact
- keystone species
Economic Importance for Humans: Positive
Because of their small size, southern two-lined salamanders are often used as bait
for recreational fishing. Their importance in the forest leaf litter and adjacent
aquatic communities may be unappreciated by most humans, but they undoubtedly contribute
to healthy forest ecosystems.
- Positive Impacts
- research and education
Economic Importance for Humans: Negative
There are no known adverse effects of
Eurycea cirrigera
on humans.
Conservation Status
This species remains relatively common in undisturbed habitats. As with all salamanders,
populations may decline or be locally extirpated due to intensive timber harvest,
other land use changes, stream pollution and siltation, or changes in soil chemistry
due to "acid rain." These salamanders often disappear from urbanized or suburbanized
landscapes.
Other Comments
Southern two-lined salamanders hybridize with other salamanders in the genus
Eurycea
, such as
northern two-Lined salamanders
. Additional studies on the extent of hybridization may indicate whether these salamanders
should remain a separate species or be reunited with their closest relatives.
Additional Links
Contributors
Jason Matthes (author), Michigan State University, James Harding (editor, instructor), Michigan State University, Tanya Dewey (editor), Animal Diversity Web.
- 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.
- freshwater
-
mainly lives in water that is not salty.
- 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.
- marsh
-
marshes are wetland areas often dominated by grasses and reeds.
- swamp
-
a wetland area that may be permanently or intermittently covered in water, often dominated by woody vegetation.
- riparian
-
Referring to something living or located adjacent to a waterbody (usually, but not always, a river or stream).
- 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.
- sexual ornamentation
-
one of the sexes (usually males) has special physical structures used in courting the other sex or fighting the same sex. For example: antlers, elongated tails, special spurs.
- polygynandrous
-
the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.
- 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
- oviparous
-
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
- fossorial
-
Referring to a burrowing life-style or behavior, specialized for digging or burrowing.
- natatorial
-
specialized for swimming
- diurnal
-
- active during the day, 2. lasting for one day.
- nocturnal
-
active during the night
- motile
-
having the capacity to move from one place to another.
- sedentary
-
remains in the same area
- hibernation
-
the state that some animals enter during winter in which normal physiological processes are significantly reduced, thus lowering the animal's energy requirements. The act or condition of passing winter in a torpid or resting state, typically involving the abandonment of homoiothermy in mammals.
- solitary
-
lives alone
- territorial
-
defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement
- visual
-
uses sight to communicate
- 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.
- keystone species
-
a species whose presence or absence strongly affects populations of other species in that area such that the extirpation of the keystone species in an area will result in the ultimate extirpation of many more species in that area (Example: sea otter).
- carnivore
-
an animal that mainly eats meat
- insectivore
-
An animal that eats mainly insects or spiders.
- molluscivore
-
eats mollusks, members of Phylum Mollusca
- 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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Bartlett, R., P. Bartlett. 2006. Guide and Reference to the Amphibians of Eastern and Central North America (North of Mexico) . Gainesville, Florida: University Press of Florida.
Burton, T., G. Lichens. 1975. Salamander populations and biomass in the Hubbard Brook Experimental Forest, New Hampshire. Copeia , 1975: 541-546.
Conant, R., J. Collins. 1998. Peterson Field Guildes: Reptiles and Amphibians of Eastern/Central North America . Boston/New York: Houghton Mifflin Company.
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Grant, W. 1955. Territorialism in two species of salamanders. Science , 121: 137-138.
Grover, M. 2000. Determinants of salamander distributions along moisture gradients. Copeia , 2000: 156-158.
Jacobs, J. 1987. A preliminary investigation of geographic variation and systematics of the two-lined salamander, Eurycea bislineata (Green).. Herpetologica , 43: 423-446.
Jakubanis, J., M. Dreslik, C. Phillips. 2008. Nest Ecology of Southern Two-Lined Salamander Eurycea cirrigera in Eastern Illinois. Northeastern Naturalist , 15(1): 131-140.
Muenz, T., S. Golladay, L. Smith, G. Vellidis. 2008. Diet and Abundance of Southern Two-Lined Salamanders ( Eurycea cirrigera ) in streams within an Agricultural Landscape, Southwest Georgia. Southeastern Naturalist , 7(4): 691-704.
Pauley, T., M. Watson. 2009. " Eurycea cirrigera Southern Two-Lined Salamander" (On-line). AMPHIBIAWEB. Accessed December 14, 2009 at http://amphibiaweb.org/cgi/amphib_query?where-genus=Eurycea&where-species=cirrigera .
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Slavens, F., K. Slavens. 1999. Reptiles and Amphibians in Captivity: Breeding, Longevity, and Inventory . Seattle, Washington: Slaveware.
Vernberg, F. 1953. Hibernation studies of two species of salamanders, Plethodon cinereus cinereus and Eurycea bislineata bislineata . Ecology , 34: 55-62.
Weichert, C. 1945. Seasonal variation in the mental gland and reproductive organs of the male Eurycea bislineata . Copeia , 1945: 78-84.