Adultcan be found in either forest (terrestrial) or streams (aquatic) depending on the time of year and whether they are mating. Usually they prefer the undersides of logs and other slightly damp locations when on land, but return to streams for mating. In the late winter, both males and females are found in streams, usually under rocks or logs, where they will mate and the female will lay her eggs. Blue Ridge two-lined salamanders require streams with suitable, submerged substrate (rocks) to oviposit under. Outside of the breeding season, many adults search out terrestrial burrows, undersides of logs, or other cover objects.
All juvenilespend at least one year in a stream for development. Thus, juveniles are found in or near streams, generally under rocks, logs, or leaf litter.
- Aquatic Biomes
- lakes and ponds
- rivers and streams
- Other Habitat Features
- Average elevation
- 1,200 m
are lungless salamanders and therefore have nasolabial grooves below each nostril. Most individuals feature fleshy extensions of the upper lip that encompass these nasolabial grooves, also known as cirri.
have two very distinct male sexual morphologies: morph wilderae males and morph A males. These two morphologies differ in their mental hedonic (lower jaw) glands, premaxillary teeth, cirria, and temporal musculature. The male wilderae have a mental hedonic gland, seasonally larger premaxillary teeth, cirri, and smaller temporal musculature, while the morph A lacks many of these characteristics and has larger temporal musculature. They do not have different habitats and they do appear very similar in appearance.
These slender salamanders range in length from 7 to 10.7 cm with a tail that makes up 55 to 60% of this total length. They are bright yellow-orange in color with two dorsolateral stripes running down the back. Between the two dorsolateral stripes, the dorsal area features many small, black spots from nose to tail. The sides are mottled with significant amounts of irregular, black spots as well. The number of costal grooves varies by elevation; populations below 1,200 meters feature 14, whereas populations above feature 15 or 16 grooves.
Eurycea bislineata, but is now recognized as its own species. is brighter in color (yellow to orange) than the browner Eurycea cirrigea and other relatives with long striped tails. (Bernardo and Reagan-Wallin, 2002; Bruce, 1986; Camp, et al., 2000)was originally thought to be a subspecies of the larger
- Sexual Dimorphism
- sexes alike
- sexes shaped differently
- Range length
- 7 to 10.7 cm
- 2.76 to 4.21 in
Eggs are placed on the underside of stream logs or in other wet depositories. After approximately 1 to 2 years, in the late spring or early summer, larvae undergo metamorphosis. This time varies according to water temperature and type of stream. Larvae of these salamanders are yellow with a dorso-lateral stripe that is dashed and contains 3 rows of unpigmented lateral line spots.
After metamorphosis, juveniles usually remain in streamside habitats for some time before they spawn. They are usually found in streams or around them for the following 3 to 4 years before they are fully sexually mature, but there have been instances where they are mature by 2 years.
First year larvae usually go downstream and adults who are ready to spawn move upstream to do so.
Sex of these species, can be determined by the cirri as well as swollen, mental hedonic glands which are located under the lower jaw. During the breeding season, some males exhibit broad heads from these swollen glands. There are two morphs in males and one female morph that can breed with either of the two male morphs. (Bruce, 1986; Bruce, 1988; Ryan, 1998; Voss, 1993)
- Development - Life Cycle
Courtship in Blue Ridge two-lined salamanders is not well documented. The presence of nasolabial grooves, which are lined with glands, and mental hedonic glands suggests that pheromones play a role in reproduction.
gather at mating sites from October through April.
There may be a correlation between having premaxillary teeth and hedonic mental and tail glands in courtship. Enlarged premaxillary teeth may be correlated with a mental hedonic gland where the teeth scrape the female's skin allowing the male's mental hedonic gland to secrete a substance that can easily enter the female's circulatory system. (Jacobs, 1987; Sever, 1989)
- Mating System
- polygynandrous (promiscuous)
Eggs are laid anywhere from early in the year to mid summer depending on the elevation. Clutch size may vary between populations, as some populations have been found to lay 8 to 34 while others lay 28 to 56. Clutches as large as 87 eggs have been reported, but this is likely a mass laid by several females.
After the eggs are fertilized, the larvae undergo metamorphosis after one to two years.larvae usually eat invertebrates and are considered top predators in many of their habitats, but are preyed on by two other salamander species. The larvae length ranges from 11 to 18 mm, with an average of 16.7 mm.
- Key Reproductive Features
- seasonal breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- Breeding interval
- breeds once yearly.
- Breeding season
- breeds from February to July.
- Range number of offspring
- 8 to 56
- Range age at sexual or reproductive maturity (female)
- 2 to 4 years
- Average age at sexual or reproductive maturity (female)
- 3 to 4 years
- Range age at sexual or reproductive maturity (male)
- 2 to 4 years
- Average age at sexual or reproductive maturity (male)
- 3 to 4 years
As far as is documented in any scientific literature, some mothers stay to guard their eggs but no additional information exists. (Voss, 1993)
- Parental Investment
the average lifespan of (Bruce, 1988)is estimated at 4.4 years, but few individuals live longer than 5 years and none have been documented older than 10 years. Factors that affect survival are poorly understood.
- Range lifespan
- 4 to 10 years
- Range lifespan
- Average lifespan
- 4.4 years
- Average lifespan
As with most salamanders,has competition based on size where larger individuals dominate over the smaller in courtship and habitat. There is little known about the social systems and competition involved in stream-dwelling salamanders, but what is known is that the larvae in these streams most likely interact and compete based on size. It may also be possible that larvae activity and behavior will be affected by the competition in the ecosystems. It is implied that the have a hierarchy based off of size.
Though activity has been observed during the day, these salamanders are most active and do much of their feeding at night. Significant migrations have not been documented for this species. They have been noted to make small movements within streams and adults perform small movements from terrestrial to aquatic habitats during the breeding season. (Wiltenmuth, 1997)
- Key Behaviors
- dominance hierarchies
There is no information regarding territories for this species.
Communication and Perception
Some of the senses that are highly developed in southern two-lined salamanders. The mating process involves tactile as well as chemical simulation. , unlike the other related salamanders, does not partake in visual stimulation by fluttering movements of the forelimbs.are used to help them distinguish between mating with their own species versus
Information on how (Kozak, 2003)perceives the environment is not well documented, but they likely perceive visual, tactile, and chemical stimuli.
Larval (Johnson and Wallace, 2005)usually feed at night on various aquatic invertebrates. These invertebrates feed on detritus and therefore limiting detritus does affect the food availability for . The invertebrates they eat include copepods, cladocerans, chironomids, nematodes, and terrestrial insects. Adults in this species eat more terrestrial organisms, but specifics have not been studied.
- Animal Foods
- terrestrial non-insect arthropods
- terrestrial worms
- other marine invertebrates
- Anti-predator Adaptations
There are no known host species of this species. Eurycea cirrigea, a closely related species, is used as a keystone species where they cycle nutrients in forest communities. However, this is speculative and may not be accurate for . (Beachy, 1994; Johnson and Wallace, 2005)
Economic Importance for Humans: Positive
does not provide any economic importance for humans.
Economic Importance for Humans: Negative
There are no known negative effects ofon humans.
is not currently considered a threatened species, and the IUCN Red List considers this species to be of least concern. However, pollution, deforestation and other human threats to their aquatic and terrestrial habitats could affect populations.
Tanvi Khanpara (author), University of Michigan-Ann Arbor, Phil Myers (editor), University of Michigan-Ann Arbor, Rachelle Sterling (editor), Special Projects.
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.
- 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.
an animal that mainly eats meat
uses smells or other chemicals to communicate
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.
- active during the day, 2. lasting for one day.
- dominance hierarchies
ranking system or pecking order among members of a long-term social group, where dominance status affects access to resources or mates
animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature
- external fertilization
fertilization takes place outside the female's body
union of egg and spermatozoan
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
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.
An animal that eats mainly insects or spiders.
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).
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.
having the capacity to move from one place to another.
This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.
specialized for swimming
- native range
the area in which the animal is naturally found, the region in which it is endemic.
active during the night
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
chemicals released into air or water that are detected by and responded to by other animals of the same species
the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.
"many forms." A species is polymorphic if its individuals can be divided into two or more easily recognized groups, based on structure, color, or other similar characteristics. The term only applies when the distinct groups can be found in the same area; graded or clinal variation throughout the range of a species (e.g. a north-to-south decrease in size) is not polymorphism. Polymorphic characteristics may be inherited because the differences have a genetic basis, or they may be the result of environmental influences. We do not consider sexual differences (i.e. sexual dimorphism), seasonal changes (e.g. change in fur color), or age-related changes to be polymorphic. Polymorphism in a local population can be an adaptation to prevent density-dependent predation, where predators preferentially prey on the most common morph.
Referring to something living or located adjacent to a waterbody (usually, but not always, a river or stream).
- scent marks
communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them
- seasonal breeding
breeding is confined to a particular season
remains in the same area
reproduction that includes combining the genetic contribution of two individuals, a male and a female
associates with others of its species; forms social groups.
uses touch to communicate
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).
Living on the ground.
uses sight to communicate
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