Southern Two-lined Salamander
© 2010 Dr. Stephen G. Tilley (1 of 93)
Country distribution from AmphibiaWeb's database: United States
Eurycea cirrigera (Green, 1830)
Thomas K. Pauley1
1. Historical versus Current Distribution. The range of southern two-lined salamanders (Eurycea cirrigera) extends from Illinois and Indiana southeast through southern Ohio, southern West Virginia and Virginia, and south through Kentucky, Tennessee, North Carolina, and South Carolina to Georgia, Alabama, Mississippi, and Louisiana (E.E. Brown, 1992; Sever, 1999b). Southern two-lined salamanders have contact zones with northern two-lined salamanders (E. bislineata) in Ohio (Guttman and Karlin, 1986), Virginia (Mitchell and Reay, 1999), and West Virginia (Montani and Pauley, 1992; Brophy, 1995). Southern two-lined salamanders are absent in eastern Ohio and northern West Virginia where northern two-lined salamanders are found, and from the southern Blue Ridge Mountains where Blue Ridge two-lined salamanders (E. wilderae) occur (Sever, 1999b). There has been some debate among systematists on the validity of assigning full species status to members of the E. bislineata complex. For a summary of the taxonomic status of this group see Guttman and Karlin (1986), Jacobs (1987), Guttman (1989), Petranka (1998), Sever (1999b), Camp et al. (2000), and Highton (2000).
Thurow (1997) reports a successful translocation and subsequent establishment of southern two-lined salamanders from western Indiana to west-central Illinois.
2. Historical versus Current Abundance. Southern two-lined salamanders appear to remain common throughout most of their range. There are no known reports of declines in abundance. Disjunct populations on the periphery of their range in northeastern Illinois apparently are the same as in the 1930s (Mierzwa, 1998). Numbers of specimens in museums from Hamilton County, Ohio, from pre-1940–'95 show the number of southern two-lined salamanders to be about the same (Davis et al., 1998). While museum records cannot identify populations trends, they can illustrate the occurrence of species. In Indiana, Minton (1998) compared historical and present abundance of amphibians and reptiles at eight sites. Southern two-lined salamanders initially were found at two sites in 1948, and their abundance was basically the same when Minton checked again in 1991 and 1993.
3. Life History Features.
A. Breeding. Reproduction is aquatic.
i. Breeding migrations. Weichert (1945) reported that during the spring breeding season, adult salamanders were found in water, but at all other times of the year two-lined salamanders in the Cincinnati, Ohio, area were found away from water. In West Virginia, they can be either associated with aquatic habitats or great distances from visible water sources during the summer. Individuals in upland, non-breeding habitats migrate to first-, second-, and third-order streams in the autumn where they remain through the winter (T.K.P., personal observations).
ii. Breeding habitat. Breeding and egg deposition occur in aquatic habitats, especially in streams. Courtship activity of southern two-lined salamanders in a laboratory setting was described by Noble and Brady (1930). They also reported that southern two-lined salamanders from North Carolina would readily mate with northern two-lined salamanders from New York. Weichert (1945) found the breeding season for southern Ohio was limited to the end of March to the first two weeks of April. Courtship occurs in the fall in North and South Carolina and Virginia (Martof et al., 1980). Brophy (1995) located a mature male and gravid female together at the end of March in southwestern West Virginia, and the female had a spermatophore visible in her cloaca, suggesting the breeding season is early spring for this region.
i. Egg deposition sites. Eggs may be deposited under rocks or leaves, attached to logs and sticks adjacent to streams (Richmond, 1945; Wood, 1953a; Baumann and Huels, 1982; Green and Pauley, 1987), or broadcast underwater among rocks and gravel in stream beds (T.K.P., personal observations). Females usually brood egg clusters (Green and Pauley, 1987; Marshall, 1996). Marshall (1996) found seven clusters of eggs in a single stream in Mississippi; three clutches were attached to the underside of logs and four were unattached and buried in the substrate. In Georgia, Martof (1955) found females in January–February to be distended with eggs and suggested that eggs were laid in February. Wood (1953a) reported that eggs were deposited over a 10-wk period from late January to mid April on the Virginia Coastal Plain. Baumann and Huels (1982) found 1–3 egg masses of two-lined salamanders in Pine Creek in southeastern Ohio attached to the undersides of rocks. Brophy (1995) found egg masses in early development between 21 March–8 April in southwestern West Virginia. Masses were ovular in shape and attached to the underside of rocks in streams. Eggs are deposited in streams under rocks and other objects in winter and spring in North and South Carolina and Virginia (Martof et al., 1980) and in May in Illinois (Smith, 1961).
ii. Clutch sizes. Baumann and Huels (1982) reported that egg masses of southern two-lined salamanders averaged 16 cm2 in total area. The number of eggs/nest reported in the literature varies greatly. The number of eggs in a clutch ranges from 12–110 and averages from 18–50 (Noble and Richards, 1932; Richmond, 1945; Wood and Duellman, 1951; Wood and McCutcheon, 1954; Smith, 1961; Mount, 1975). Differences in the number of ova reported are likely due to differences in the body size of females (Wood and McCutcheon, 1954). Barbour (1971) reported 30 eggs/clutch in Kentucky, and Brophy (1995) found clutch sizes from 36–59 eggs in southwestern West Virginia. Clutches were commonly made up of around 40 eggs. Large counts of 200 or more eggs in a nest may be the result of communal nests (Baumann and Huels, 1982).
In Illinois, eggs hatch about 1 mo after deposition (Smith, 1961). In northern Georgia, hatching occurs in early March (Martof, 1955). Duellman and Wood (1954) found that eggs hatch in late June in southwestern Ohio, where hatchlings are < 9 mm SVL. Reports of newly hatched larvae vary from 10.5 mm (TL) in Louisiana (Dundee and Rossman, 1989) to 13 mm in Kentucky (Barbour, 1971).
i. Length of larval stage. The larval period of southern two-lined salamanders lasts from 1–3 yr. Lengths of the larval stage range from 2 yr (Petranka, 1984b) to 2–3 yr in Kentucky (Barbour, 1971); 1–3 yr in Alabama (Mount, 1975); 1–2 yr in Louisiana (Dundee and Rossman, 1989); 2 yr in Illinois (Phillips et al., 1999) and Ohio (Duellman and Wood, 1954); and possibly 3 yr in West Virginia (Pollio, 2000). A small number of larvae transform during the third year in Ohio (Duellman and Wood, 1954). Brophy (1995) found two size classes of larvae from southern and southwestern West Virginia. First-year larvae from a pond-dwelling population grew significantly faster than a stream-dwelling population, but the stream-dwelling population grew significantly faster in the second year. Larvae from both populations grew little during cooler months (Brophy, 1995). Some larvae can reach the same size as sexually mature adults.
ii. Larval requirements.
a. Food. Larval southern two-lined salamanders are euryphagous feeders. Prey items usually are invertebrates and include ostracods, copepods, and insects such as dipterans (chironomids), ephemeropterans, and coleopterans (dytiscid beetle larvae; Caldwell and Houtcooper, 1973; Petranka, 1998). In a comparison of prey items between pond- and stream-dwelling larval populations in southern West Virginia, Brophy and Pauley (2000) found that pond larvae consumed 9 prey taxa, while stream larvae consumed 15. Primary prey for pond larvae included ostracods and chironomid larvae; stream larvae fed on copepods, isopods, and chironomids.
Southern two-lined salamander larvae will also prey on vertebrates. Petranka (1984b) observed that large larvae will prey heavily on stream salamander (Ambystoma barbouri) larvae.
b. Cover. Petranka (1984b) found that larvae showed diurnal movements to and from cover objects, and that larvae feed along streambeds during darkness. Smith and Grossman (2003) show that microhabitat use is correlated with habitat heterogeneity and the availability of cover.
iii. Larval polymorphisms. Unknown and unlikely.
iv. Features of metamorphosis. Size of larvae at transformation has been reported at 52 mm (TL) in Kentucky (Petranka, 1984b); 52 mm TL for males and 50.9 mm TL for females in southwestern Ohio (Duellman and Wood, 1954); 72 mm TL in Georgia (Martof, 1955); and 34–40.2 mm SVL in Ohio and Indiana populations (Sever, 1972).
v. Post-metamorphic migrations. Migrations occur from pond and stream habitats to adjacent uplands. Martof (1955) found transforming larvae in September in Georgia. Duellman and Wood (1954) discovered transformed individuals in southwestern Ohio during the summer. Transformation occurs in May to mid June in Kentucky (Petranka, 1984b). Early metamorphic animals from a southern West Virginia pond in August were composed of two size classes, suggesting that these individuals had metamorphosed from 1–2-yr larvae (Brophy, 1995).
vi. Neoteny. Mount (1975) reported that neotenic individuals are not uncommon in Alabama. This condition has not been reported in other areas of the range of southern two-lined salamanders, but needs further study.
D. Juvenile Habitat. Juveniles are found under stones and other cover objects at the edges of aquatic habitats (Hudson, 1955; Petranka, 1998) and in surrounding forests (Petranka, 1998).
E. Adult Habitat. Southern two-lined salamanders are a semi-aquatic species and can be found in a variety of habitats throughout its range such as streams, pools, seeps, ditches and damp woods (Smith, 1961; Barbour, 1971; Minton, 1972, 2001; Mount, 1975; Martof et al., 1980; Green and Pauley, 1987; Dundee and Rossman, 1989; Guttman, 1989; Bartlett and Bartlett, 1999a; Phillips et al., 1999). Ashton and Ashton (1978) reported that two-lined salamanders frequently used stream habitats with coarse sand and gravel, as well as broken limestone rock, leaf litter, and crayfish burrows. Brophy (1995) found southern two-lined salamanders mostly within the stream banks of two southwestern West Virginia streams. Martof (1955) suggested southern two-lined salamanders are abundant around springs and small streams in north-central Georgia. Grover (2000) reported that southern two-lined salamanders found along streams with black-bellied salamanders (Desmognathus quadramaculatus) were captured farther from streams than in an area without black-bellied salamanders. Means (2000) found southern two-lined salamanders most often around the heads of ravines in the coastal plain.
F. Home Range Size. In laboratory experiments, two-lined salamanders demonstrated a home range size that extended for a 5–6 inch radius from a central shelter site (Grant, 1955). In natural habitats, home range size is probably much larger. A mark-recapture study by Brophy (1995) suggested that the home range size of southern two-lined salamanders from southwestern West Virginia was around 14 m2.
G. Territories. Grant (1955) showed in laboratory experiments that two-lined salamanders defend territories from conspecifics by advancing toward an intruder and placing their snout in contact with it. In other cases, the salamander defending a territory would bite the snout or tail, often resulting in autotomy of the antagonist’s tail.
H. Aestivation/Avoiding Dessication. Aestivation studies have not been reported in the literature, but southern two-lined salamanders, as with other plethodontids, probably remain in refugia underground during drought conditions.
Brooks and Sassaman (1965) measured the critical thermal maximum (CTM) of larval and adult Eurycea from the coastal plain of Virginia. The average CTM of larvae was 33.3 ˚C and 34.6 ˚C for adults.
Grover (2000) measured the dehydration and rehydration rates of E. cirrigera. The rehydration rate of E. cirrigera was intermediate to that of Plethodon glutinosus and D. monticola.
I. Seasonal Migrations. Ashton and Ashton (1978) reported that when stream temperatures fell below 7 ˚C, southern two-lined salamanders moved upstream to winter refugia but remained within close proximity to the stream. Brophy (1995) found no cyclic movements of southern two-lined salamanders in two populations from southwestern West Virginia.
J. Torpor (Hibernation). In an experimental hibernation study, Vernberg (1953) observed that southern two-lined salamanders, in response to an artificial temperature gradient, burrowed into smooth-walled hibernacula 25–30 cm into soil. Weichert (1945) found active southern two-lined salamanders on warm days during the winter in southern Ohio. Similarly, Ashton and Ashton (1978) observed movement during winter in refugia with moderate conditions.
K. Interspecific Associations/Exclusions. Southern two-lined salamanders are associated with other stream-dwelling salamanders including black-bellied salamanders, northern dusky salamanders (Desmognathus fuscus), seal salamanders (D. monticola), and spring salamanders (Gyrinophilus p. porphyriticus). Means (2000) described an assemblage of plethodontid salamanders that inhabit the steephead ravines of the coastal plain that included southern two-lined salamanders, red salamanders (Pseudotriton ruber), and either Apalachicola dusky salamanders (D. apalachicolae) or spotted dusky salamanders (D. conanti).
Northern two-lined salamanders and southern two-lined salamanders will hybridize (Noble and Brady, 1930), and broad regions of intergradation exist between these forms of two-lined salamanders (Howell and Switzer, 1953; Mittleman, 1966).
L. Age/Size at Reproductive Maturity. In Ohio, sexual maturity is reached in 2–4 yr (Guttman, 1989). Age and size at sexual maturity vary according to the length of the larval period and season when transformation of larvae occurs.
M. Longevity. Unknown.
N. Feeding Behavior. Weichert (1945) reported the stomach contents of southern two-lined salamanders from southern Ohio included small wood roaches, spiders, ticks, earthworms, beetles, isopods, millipedes, small snails, grubs, springtails, and dipteran and hymenopteran insects. Food was found in stomachs from every month of the year.
O. Predators. Wood (1953a) suggested that mosquito fish (Gambusia affinis holbrookii) ate two-lined salamander eggs.
Resetarits (1991) showed that brook trout (Salvelinus fontinalis) and crayfish (Cambarus bartonii) were predators of Eurycea larvae in a Virginia stream, and the presence or absence of trout could alter the salamander assemblages in the stream. Gustafson (1994) showed that spring salamander larvae preyed upon southern two-lined salamander larvae during laboratory experiments, and the efficiency of spring salamanders as predators of southern two-lined salamanders increased with the size of spring salamander larvae. Petranka (1984b) reported that larvae were palatable to sunfish and darters in streams.
Grover (2000) found that the presence of black-bellied salamanders in streams caused a shift of southern two-lined salamanders to drier sites farther from streams, suggesting that black-bellied salamanders were predators of southern two-lined salamanders. Other predators of two-lined salamanders (including other members of the E. bislineata complex) include screech owls, common garter snakes (Thamnophis sirtalis), ring-necked snakes (Diadophis punctatus), and rainbow trout (Oncorhynchus mykiss; Huheey and Stupka, 1967; Rising and Schueler, 1980; Beachy, 1993b).
P. Anti-Predator Mechanisms. Eggs of southern two-lined salamanders are deposited in cryptic sites under logs, leaves, and rocks. Females often are seen tending the eggs as a defense against predators (Baumann and Huels, 1982).
Petranka (1984b) suggested that diurnal behavior might be an anti-predator mechanism in larvae. Larvae may also use chemical cues from predatory fish to increase use of refugia (Petranka et al., 1987; Kats et al., 1988).
Several anti-predator mechanisms of northern two-lined salamander adults have been reported. The behavior of southern two-lined salamanders is probably similar to that of northern two-lined salamanders. In a laboratory setting, northern two-lined salamanders responded to common garter snakes with a protean, flipping escape rather than posturing or undulating the tail (Ducey and Brodie, 1983). Salamanders with tails could autotomize the tail during an encounter with a snake and were more successful in escaping capture than salamanders without tails. Dowdey and Brodie (1989) showed that different densities of predators can affect the response of two-lined salamanders to those predators. Salamanders in a high density of northwestern garter snakes (T. ordinoides) ran away more than salamanders from other areas. Salamanders that ran had a survival advantage. Whiteman and Wissinger (1991) reported that tail autotomy during predation experiments with common garter snakes as predators was nearly twice as frequent in northern two-lined salamanders as in northern dusky salamanders or Allegheny Mountain dusky salamanders (D. ochrophaeus). They found that two-lined salamanders with tails were more likely to escape a predator than those without tails. Two-lined salamanders were less aggressive during encounters and bit garter snakes less frequently than dusky salamanders.
Q. Diseases. Not known.
R. Parasites. Rankin (1937) lists the protozoan Prowazekella longifilis, the trematode Brachycoelium hospitale, and proteocephalid cestode cysts from southern two-lined salamanders.
4. Conservation. Southern two-lined salamanders are abundant throughout most of the range. They are found in water polluted with sewage and other organic matter. As with most forest salamanders, major concerns are habitat destruction through activities such as clearcutting and habitat degradation, including acid mine drainage and acid deposition.
1Thomas K. Pauley
2Mark B. Watson
Literature references for Amphibian Declines: The Conservation Status of United States Species, edited by Michael Lannoo, are here.
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Citation: AmphibiaWeb. 2019. <http://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 20 Mar 2019.
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