Amphibians of North Carolina

Scientific Name:	Common Name:		Family (Alpha):

NC Records
Plethodontidae Members:
Eurycea cirrigera - Southern Two-lined Salamander

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Taxonomy

Class: Amphibia

Order: Caudata

Family: Plethodontidae

Subfamily: Spelerpinae


Taxonomic Comments: Eurycea cirrigera is a member of the Eurycea bislineata species complex, which includes a group of stream-breeding salamanders that are found in eastern North America, many of which are referred to as two-lined salamanders. One wide-ranging member, Eurycea bislineata, was traditionally treated as a polytypic species that contained three subspecies (E. b. bislineata; E. b. wilderae; E. b. cirrigera). Jacobs (1987) conducted a broadscale survey of allozyme patterns of populations across the eastern US and found several genetically differentiated groups. He recommended that the subspecies of E. bislineata be raised to the species level based on genetic distances between groups. Subsequent studies of contact zones support recognizing these as full species (e.g., Pierson et al. 2021), with E. wilderae being a lineage that is mostly restricted to the southern Appalachian Mountains. Kozak et al. (2006) conducted a mtDNA analysis of populations of the Eurycea bislineata species complex across the eastern US. They were able to delineate 13 major phylogenetically and geographically distinct lineages that were associated with pre-Pleistocene drainage patterns in eastern North America. Data from Kozak et al. (2006) and Jacob (1987) indicate that both E. wilderae and E. cirrigera are polyphyletic lineages, and that the recognition of additional species may be warranted in the future. The recent description of the Carolina Sandhills Salamander (E. arenicola) is the first of what will likely be several new species that are described from populations that are currently recognized as either E. wilderae or E. cirrigera. Stuart et al. (2020) provide a comprehensive review of the systematics of the Eurycea bislineata species complex.
Species Comments:

Identification

Description: Eurycea cirrigera is a small, slender plethodontid that has a ground color that varies from greenish yellow to tan or orange. Each side has a black dorsolateral stripe that extends from immediately behind the eye onto the tail. The stripe typically continues for at least half the length of the tail, and frequently almost to the tip, before breaking up into a series of spots. The dorsum usually contains numerous, scattered black spots or blotches and the venter is yellowish. The sides of the body below the stripes have varying degrees of scattered black spots or blotches, and there is often a series of lighter spots immediately below the stripe that extend from near the front legs onto the tail. The elongated tail is laterally compressed and constitutes about 55-60% of the total length (Sever 1999a). Average adult size is similar between the sexes, and local populations often vary substantially in average size. The average SVL of adults in local populations varies from around 34-40 mm, and there are 14 costal grooves between the limbs (Sever 1999a).

Sexually-active males in many populations, including those in North Carolina, develop elongated cirri, swollen, fan-shaped mental glands, and elongated, unicuspid, premaxillary teeth. The teeth often pierce the male's lip and are used to abrade the female's skin and introduce mental gland secretions into the female's circulatory system during courtship. The cirri and mental glands are less evident during other times of the year, and the teeth are shed after breeding and replaced with smaller, bicuspid teeth. Males in certain populations in Ohio, Kentucky, and West Virginia lack cirri but develop an enlarged temporal musculature during the breeding season (Brophy and Pauley 2002). At lower elevation sites along the Blue Ridge Escarpment where E. cirrigera and E. wilderae meet, both species have 14 costal grooves and the adults of these two species are largely indistinguishable. The extent to which the black stripes extend onto the tail varies markedly in both species, and it is not a diagnostic trait (Sever 1999a). However, the general tendency for the stripe to continue farther towards the tail tip in E. cirrigera works as a general rule.

The larvae are indistinguishable from those of E. wilderae (Sever, 1999a). The hatchlings average around 7-9 mm SVL and 11- 14 mm TL (Petranka 1998), and the larvae are dusky colored above with 6-9 pairs of light dorsolateral spots on the body. The body is streamlined and the tail fin stops near the insertion of the rear limbs. The venter is light colored with numerous iridophores. Hatchlings and young larvae superficially resemble Desmognathus larvae but have reddish gills with longer and more slender rami, along with a more squared rather than rounded snout as seen in Desmognathus larvae.

Online Photos: Google iNaturalist

AmphibiaWeb Account

Distribution in North Carolina

Distribution Comments: As currently defined, the range of E. cirrigera extends from a line from roughly central Indiana, southwestern Ohio, southern West Virginia, and central Virginia southward to northern Florida and the Gulf Coast states. Populations are largely confined to areas east of the Mississippi River and are absent from most of the Blue Ridge where they are replaced by E. wilderae. In North Carolina, populations are found throughout most of the Piedmont and Coastal Plain. They are absent or uncommon in the Sandhills region and the eastern portion of the northern coastal region. This species is replaced by E. wilderae along the Blue Ridge Escarpment, but the exact boundary between the two species is poorly defined.
County Map: Clicking on a county returns the records for the species in that county.


GBIF Global Distribution

Key Habitat Requirements

Habitat: This wide-ranging species uses a variety of habitats. In areas outside of the Coastal Plain the larvae are most commonly found in lower order streams that are surrounded by hardwood or mixed hardwood-conifer forests. Perennial streams with rocky substrates, minimal siltation, healthy invertebrate populations, and adequate cover for the larvae provide optimal habitats (Petranka 1998, Smith and Grossman 2003). The juveniles and adults live on land. They can be more or less semiaquatic at some sites, while at others fully terrestrial and found far from the breeding sites. Mature hardwood forests with abundant rocks, logs and other surface cover provide optimal habitats for the juveniles and adults.

Coastal Plain populations are often associated with perennial springs, headwater seepage wetlands, ravine heads and small streams in hardwood forests or swamplands. The juveniles and adults are generally found closer to water than more upland and northern populations. On rare occasions, eggs or larvae have been found in sluggish or standing water, including a stagnant drainage ditch in Virginia (Wood 1953) and a small woodland pond in West Virginia (Brophy and Pauley 1997).

Biotic Relationships: The larvae live in perennial streams that support an array of predators such as crayfishes, small fishes, and larger salamander larvae. Some of the known predators include the Brook Trout, sunfishes, darters, crayfishes, and Spring Salamander larvae (Gustafson 1994, Petranka 1984, Resetarits 1991).

The larvae have behavioral defenses against fish and other predators. Larvae in central Kentucky are primarily active outside of cover at night when fish are inactive and use chemical cues to monitor the presence of fish. Larvae respond to fish chemicals by seeking refuge beneath cover objects (Kats et al. 1988, Petranka et al. 1987). Field experiments in Virginia also indicate that larvae reduce their surface activity when confined with predatory Brook Trout and Spring Salamander larvae (Resetarits 1991). Gyrinophilus in this study did not significantly affect the survival of Eurycea, but did reduce larval growth rates. Gustafson (1994) examined predator-prey interactions between G. porphyriticus larvae and E. cirrigera larvae in experimental streams and found that the predation rates on Eurycea increased with the size of Gyrinophilus. Eurycea larvae also restricted their nighttime surface activity in the presence of Gyrinophilus and were more likely to remain in cover in the presence of large Gyrinophilus larvae.

Although poorly documented, the terrestrial juveniles and adults are very likely eaten by predators that regularly consume salamanders such as the Eastern Screech Owl, Common Gartersnake (Thamnophis sirtalis), and Ring-necked Snake (Diadophis punctatus). Mammals such as shrews, raccoons, minks, and opposums undoubtedly take them also.

See also Habitat Account for Wet-Mesic Forests with Seepages/Headwater Streams

Life History and Autecology

Breeding and Courtship: The adults in many populations live in forests that adjoin the breeding sites and undergo seasonal migrations to springs, seepages, and streams during the autumn. They remain in the immediate vicinity of the breeding sites until the spring warm-up or until the eggs hatch, then move back to forested sites. Although poorly documented, courtship and mating appears to occur both during the autumn and spring months (Sever 1989, Weichert 1945).

Kozak (2003) observed the courtship behavior of E. cirrigera from South Carolina and E. wilderae from western North Carolina and found them to be indistinguishable. The major components included an orientation phase, a persuasion phase, and sperm transfer. Orientation involved the male approaching and following the female, while the persuasion phase involved tactile and chemical stimulation by the male. After encountering a female, the two often stand side-by-side, then raise their heads, arch their dorsums, and touch cheeks. Both sexes then simultaneously rub cheeks in a circular motion. The male next engages in a persuasion phase where he moves his chin in lateral and circular motions over the female's head, dorsum, and tail. The male may later place his head on the dorsum of the female and pull his head back either slowly in one or several short strokes, or rapidly in a snapping motion. This causes the elongated teeth of the male to scratch the skin of the female and introduce pheromones from the mental gland. The pair eventually engages in a tail-straddle walk in which the female places her head on the male's tail and is led forward. The male eventually deposits a spermatophore, then moves his tail to the side of his body while arching it at a 90 degree angle above his body. The female responds by moving forward and inserting the spermatophore in her cloaca.

Reproductive Mode: Females in most populations lay their eggs during or shortly after the spring warm-up, but the breeding season of local populations varies depending on the prevailing climate and water temperatures. Egg laying can begin as early as late-January in coastal Virginia (Wood and McCutcheon 1954), but more typically occurs from mid-March through mid-May in most areas of the range (Baumann and Huels 1982, Green and Pauley 1987, Marshall 1996, Minton 1972, Weichert 1945). Brimley (1896) observed breeding in central North Carolina from December through March. Niemiller and Miller (2007) observed an unusual instance of nine females laying eggs deep within a cave in Tennessee, with six clutches found on 26 January that were estimated to have been laid as early as the first week of January. Eggs in surface streams were laid in February.

Females that breed in rocky streams typically attach eggs singly to the undersides of submerged rocks in a tight monolayer. Baumann and Huels (1982) found 49 nests in Ohio that were attached to the undersides of rocks that were embedded in the stream bottom, but had submerged cavities. The eggs were deposited in tight clusters that average 50 x 32 mm and were usually accompanied by one or more adults. Two or three clutches with attending females were often found under the same rock, which has been documented elsewhere (e.g., Jakubanis et al. 2008). Six clutches that were found by Brophy and Pauley (2002) in two study streams in West Virginia were in cool, shallow, swiftly flowing riffle sections and were also deposited in tight clusters that averaged 47 x 36 mm. The egg diameters ranged from 2.9-3.5 mm. Females in two Georgia Piedmont streams selected relatively shallow areas with cobble near the heads of riffles, as well as larger boulders (Guy et al. 2004).

In Coastal Plain streams that lack rocks, the eggs are attached to other substrates such as root fibers, leaves, aquatic plants, logs, and planks (Petranka 1998). In Virginia, eggs that were placed on the undersides of leaves, planks or logs were usually in fairly tight clusters, while those placed on rootlets or aquatic plants were sometimes scattered over a relatively large area (Richmond 1945, Wood 1953). Noble and Richards (1932) report similar modes of egg deposition in a rockless Coastal Plain stream in North Carolina. When the authors presented gravid females from this population with a choice of aquatic plants or rocks, they oviposited on rocks. Oswald et al. (2015) examined nest-site selection using coverboards in headwater seepage wetlands in the Coastal Plain of South Carolina and found that females prefer microhabitats that are relatively shallow and warm. Females preferred areas that were slightly saturated with water, as opposed to areas with deeper standing water or channels of flowing water. Nesting throughout the range usually occurs in running water, but Wood (1953) found eggs in a stagnant drainage ditch in Virginia, while Brophy and Pauley (1997) found larvae is a small woodland pond in West Virginia.

The freshly laid eggs are white to pale yellow, about 2.5-3.0 mm in diameter, and are surrounded by two jelly membranes. Each egg is suspended by a short broad stalk to a support structure such as a rock. With time, the stalk and egg membranes become flimsy and the eggs dangle freely in the water (Petranka 1998). Females often remain with their eggs through hatching and probably defend them from predators such as small crayfishes and invertebrates. However, the egg clutches are commonly found without attending females (Guy et al. 2004, Jakubanis et al. 2008, Wood and McCutcheon 1954).

Estimates of the mean clutch size based on counts of eggs in nests include 39 (range = 15-110 eggs) for an Ohio population (Baumann and Huels 1982), 30 (1-117) for two Illinois populations (Jakubanis et al. 2008), 52 (18-96) for a Virginia population (Wood and McCutcheon 1954), 55 (32-71) for a Tennessee population (Niemiller and Miller 2007), 36 (10-72) for two Georgia populations (Guy et al. 2004), 53 for a Mississippi population (Marshall 1996) and 47 (36-59) for West Virginia populations (Brophy and Pauley 2002). Mount (1975) reported the mean clutch size for Alabama specimens based on ovarian egg counts as 50 (15-114). The number of ovarian eggs increases with the female's SVL in some populations, but others have found no relationship between female SVL and the number of eggs in nests (e.g., Jakubanis et al. 2008).

The incubation period is poorly documented for this species, but presumably takes 4-8 weeks as seen in other members of the E. bislineata complex at similar latitudes (Petranka 1998). Hatching occurs in late May and June in central Kentucky (Petranka 1984), but embryos in southern or coastal populations probably hatch as early as February or March. Niemiller and Miller (2007) observed hatchlings on 26 February at a cave site in Tennessee.

Aquatic Life History: The hatchlings have conspicuous yolk reserves and likely delay feeding until most of the yolk is resorbed (Petranka 1998). The larvae are not powerful swimmers and live in slow-moving sections of streams where they prowl slowly over stream bottoms and rocks in search of small prey, particularly chironomid larvae and small zooplankton. Caldwell and Houtcooper (1973) found that chironomid larvae, copepods, fly pupae, and stonefly nymphs were the most important prey of larvae in Indiana, while Muenz et al. (2008) found chironomids, cladocerans, copepods, and ostracods to be important prey in streams in the Georgia Coastal Plain. Brophy and Pauley (1997) compared a pond and stream-breeding population in West Virginia and found chironomid larvae and ostracods to be the primary prey of pond larvae versus copepods, isopods, and chironomid larvae in stream larvae.

Petranka (1984) studied the feeding behavior and diet of larvae in a central Kentucky population. The larvae remained beneath cover objects during the day, but emerge at night and foraged on the stream bottom where they mostly fed on benthic invertebrates. Larvae of all sizes fed continuously over a 24-h period and had similar diurnal patterns of movement. The larvae appeared to be generalist, gape-limited predators that incorporated larger prey into their diet with age, but continued to take large numbers of very small prey. The major prey items included isopods, amphipods, chironomid larvae, ostracods, and copepods. The largest larvae preyed rather heavily on hatchlings of the Streamside Salamander (Ambystoma barbouri) for a short period of time in mid-April.

The larval period lasts from 1-3 years depending on local site conditions. Duellman and Wood (1954) found that most larvae in an Ohio population metamorphosed when about 2-years old and 23-32 mm SVL, but a small percentage overwintered and transformed when 3-years old. Sever (1972) noted that in Ohio and Indiana populations the larvae transform when 34–40 mm SVL. Petranka (1984) estimated the larval period to last only one year in a central Kentucky population with larvae transforming when around 52 mm TL, while Mount (1975) reported the larval period to last 1-3 years in Alabama populations. Others report the larval period to last for 1–2 years in Louisiana (Dundee and Rossman 1989), 1 year in the Georgia Piedmont (Smith and Grossman 2003), 2 years in Illinois (Phillips et al. 1999), and 2-3 years in Kentucky (Barbour 1971). Metamorphosis occurs during the warmer months of the year, typically from May to as late as August or September depending on the locale (Petranka 1998).

Terrestrial Life History: The extent to which the juveniles and adults live in the surrounding forest varies depending on local site conditions. In some populations, individuals tend to stay close to springs, seepages, and stream margins year-round, while in others they disperse more widely into the forest and undergo seasonal migrations to and from the breeding sites (Petranka 1998). Individuals in northern populations often move below ground during cold spells. Most radioactively tagged adults in a southern Ohio population remained in the vicinity of streams during the warm months and moved < 10 m between monitoring periods (Ashton and Ashton 1978). During cold weather they moved to relatively warm streambank retreats that were 8-82 cm beneath the soil surface. Adults placed in soil enclosures by Vernberg (1953) retreated underground with the onset of cold weather and were > 28 cm beneath the surface by late February.

The juveniles and adults feed year-round except during the coldest winter months in northern populations (Ashton and Ashton 1978, Weichert 1945). Dietary items in a southwestern Ohio population included wood roaches, spiders, ticks, earthworms, isopods, millipedes, beetles, snails, springtails, flies, and hymenopterans (Weichert 1945). During the warmer months of the year the juveniles and adults emerge at night and feed on small invertebrates on the forest floor or along streambanks (Petranka 1998). Surface activity in an Ohio population that was studied by Holomuzki (1980) was greatest during the first hour after dark and correlates with a peak in the activity of potential prey. Muncy et al. (2014) found that adults in a Piedmont stream in North Carolina retreated to the stream during droughts and suffered higher mortality during periods of drought.

General Ecology

Adverse Environmental Impacts

Effects of Pollution: Mountaintop removal in Appalachian has outright destroyed many headwater populations via burial, and drainage from mine sites are adversely affecting E. cirrigera and other stream-breeding salamanders and their prey (Hutton et al. 2020, Price et al. 2016). Acid drainage from old surface-mining sites can also severely deplete salamander communities (e.g., Schorr et al. 2013).

Status in North Carolina

NHP State Rank: S5

Global Rank: G5

Environmental Threats: Many of the small streams used by this species have been impacted by deforestation, agricultural activities and urbanization. Muenz et al. (2008) found very few larvae in two streams in Georgia with unfenced areas that allowed cattle to enter the water relative to streams that were fenced. Willson and Dorcas (2003) surveyed stream in the Piedmont of North Carolina and found that the relative abundance of both E. cirrigera and Desmognathus fuscus was strongly inversely proportional to the percentage of disturbed habitat in the entire watershed. The presence of woodland buffers did not effectively mitigate these adverse basinwide effects. Price et al. (2006, 2010) documented the decline and loss of both E. cirrigera and D. fuscus populations following rapid urbanization in the Piedmont of North Carolina. Similarly, Miller et al. (2007) found that larval E. cirrigera abundance decreased with the percentage of impervious surface cover such as rooftops, roads, and parking lots in Wake County. As seen in other studies, local salamander abundance was not affected by the width of forested riparian buffer zones that were present at sites. This reflects the fact that the overall adverse effects of basin-wide disturbance often outweigh the beneficial effects of local forest buffers. Barrett et al. (2010) provided evidence that the decline in abundance of larval E. cirrigera in urban areas may be due to washout from more severe and frequent flooding that is related to the high amount of impervious structures in cities.

Photo Gallery for Eurycea cirrigera - Southern Two-lined Salamander		11 photos are shown.
	Recorded by: Steve Hall, Bruce Sorrie, Scott Pohlman, Mary Conlin, and Paul Camp Chatham Co.	Recorded by: David George, Jeff Niznik Chatham Co.
	Recorded by: Paul Hart Harnett Co.	Recorded by: A. Kauppila Burke Co.
	Recorded by: L. Knepp Surry Co.	Recorded by: Rob Van Epps Mecklenburg Co.
	Recorded by: L. Osteen Orange Co.	Recorded by: Steve Hall Orange Co. Comment: A mature larvae that is beginning to metamorphose.
	Recorded by: Steve Hall and Harry LeGrand Granville Co.	Recorded by: Steve Hall Halifax Co.
	Recorded by: Steve Hall and Dawson Sather Orange Co.

Eurycea cirrigera - Southern Two-lined Salamander

Photo Gallery for Eurycea cirrigera - Southern Two-lined Salamander

11 photos are shown.