Description
Eurycea arenicola is a small, slender member of the E. bislineata complex with an overall total length of 56.0 - 89.1 mm, a snout-vent length of 28.6 - 41.3 mm, and a tail length that is 42.4 - 55.6% of the total length. Males range in total length from 56.0 - 89.1 mm, in snout-vent length from 28.6 - 41.3 mm, and in tail length from 27.4 - 49.6 mm. Females range in total length from 59.9 - 87.8 mm, in snout-vent length from 28.7 - 40.3 mm, and in tail length from 27.0 - 48.2 mm. The head is longer than wide and has the same width as the body. The short snout is almost truncate in the dorsal view and slightly rounded and protruding over the jaw in the profile. The nostrils are parallel to the snout tip and located close to the snout tip. They are visible from the dorsal view. A weak nasolabial groove can be seen. Males have nasal cirri that are located halfway between the nares and the snout tip. The interorbital distance is twice the width of the upper eyelid. The eye diameter is shorter than the snout length. Males have a weak fan-shaped mental gland on the anterior half of the chin (Stuart et al. 2020).

The trunk is marginally wider than deep and has fourteen costal grooves. The tail is slender and laterally compressed. Cross-sections of the tail at the base are oval and tapers to the tip. There are no fins on the tail. The forelimbs are small with fingers that have relative lengths of I < IV < II < III. The hind limbs are longer than the forelimbs and have toes with relative lengths of I < V < II < IV < III. The digits don't have webbing (Stuart et al. 2020).

Larvae with fully developed limbs have total length ranges from 26.6 - 51.9 mm. The head is compressed with a sloping snout in the profile. The gills have short rami and shorter fimbriae. The digits are short. The dorsal and ventral tail fins begin at the base of the tail and become their widest at the distal one-third of the tail. The dorsal fin's maximum depth is around twice that of the ventral fin. The fins extend slightly beyond the tail tip and are obtusely pointed in the profile (Stuart et al. 2020).

The presences of cirri in adult males and the lack of stripes in all adults distinguishes E. arenicola from E. aquatica, E. bislineata and E. cirrigera. The lack of dorsal spots in E. arenicola further differentiates it from E. bislineata and E. cirrigera. The lack of dorsal stripes and spots in E. arenicola also differentiate it from E. wilderae. Eurycea arenicola tend to be smaller than E. bislneata, E. cirrigera and E. wilderae. Male E. arenicola have narrower heads than E. bislineata, E. cirrigera and E. wilderae Morph A males, however male E. arenicola have broader heads than searching male E. wilderae. Female E. arenicola tend to be more slender than female E. cirrigera and have broader heads than E. wilderae females. In general, E. arenicola are more slender than E. junaluska with the former also having a more slender tail in the profile. Additionally, the tail depth in E. arenicola is much smaller than the depth of the head while the tail depth in E. junaluska is approximately equal to the head depth. The two species also differ in background coloration with E. arenicola being orange to red while E. junaluska is deep olive green to brown. From E. wallacei, a slender body and legs, dorsal coloration, normally developed eyes, and lack of paedomorphic adults in E. arenicola distinguish the two (Stuart et al. 2020).

In life, adult background color of the dorsal and lateral surfaces is olive yellow, orange, reddish orange, or red. There is a row of irregular dorsalateral black spots that starts somewhere between the posterior margin of the eye or jaw and extends to the anterior half of the tail or runs along the full tail. At the anterior end, the spots are more rounded or squared while towards the posterior they are larger, more elongated and rectangular. Smaller black spots are scattered on the dorsal surface of the head and body and on the flanks and lateral surfaces of the anterior half of the tail. The ventrum is an immaculate orange that is lighter than the dorsum. The chin and the lower jaw are yellow orange. The eye is bronze and the horizontally oval iris is black. In preservative, the dorsal surfaces fade to tan yellow while the lateral and ventral surfaces fade to creamy white. The spots fade to dark brown (Stuart et al. 2020).

Larvae, in life, vary in dorsal and lateral background coloration from brown to olive-yellow. They have irregular, dark-brown spots and flecks on the head and body. Some spots have small, distinct, cream spots in the the center. The gill rami are red and the fimbriae are pink. In preservative, the dorsal and lateral surfaces are brown. Most of the dark spots remain dark-brown, however, some of the larger ones become creamy. The spots on the ventral part of the flanks merges into the immaculate cream coloration of the belly. A creamy oblique blotch extends from the ventral surface of the eye to the corners of the he jaw. The tail fins have brown mottling (Stuart et al. 2020).

Adult vary in coloration and in where the dorsolateral spotting begins and ends. Dorsal and lateral background coloration ranges from olive yellow, orange, reddish orange, to red. Spotting typically begins at the posterior margin of the eye, but in some individuals it can begin at the posterior region of the jaw. Spotting ends either at the halfway point of the tail or run the full length of the tail. Females are longer than males in body length and males have secondary sexual characters: cirri, mental glands, and enlarge premaxillary teeth (Stuart et al. 2020).

In preservative, larvae vary in the amount and distinctiveness of their patterning on the head and body. In life, larvae vary in dorsal and lateral surfaces coloration from brown to olive green (Stuart et al. 2020).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: United States

U.S. state distribution from AmphibiaWeb's database: North Carolina

View distribution map in BerkeleyMapper.

Historically, the Carolina Sandhills salamander (Eurycea arenicola) was known only from the Sandhills region of North Carolina, with vouchered localities in Harnett, Hoke, Montgomery, Moore, Richmond, Robeson, and Scotland counties (Beane et al. 2010; Stuart et al. 2020). There is no evidence to support a difference between historical and current distributions. Future fieldwork could serve to slightly expand the known range, especially to the south or east.

Life History, Abundance, Activity, and Special Behaviors
Reproduction in E. arenicola is aquatic with the salamanders having a biphasic life cycle: adults are semi-terrestrial; eggs and larvae are aquatic (Stuart et al. 2020). Breeding and post-metamorphic migrations are unknown, but these probably involve only limited, short-distance movements to the breeding habitats from immediately adjacent uplands. No mass or synchronous migrations are known.

Carolina Sandhills salamanders breed in springs and blackwater streams with substrates of sand, gravel, clay, or detritus at elevations of 51 - 150 m within the longleaf pine ecosystem. Courtship has not been described, but a male and gravid female were found together beneath a board on 5 December, and gravid females have been found in late fall and early winter (Stuart et al. 2020).

Eggs have been found attached to submerged root masses in streams. Oviposition typically occurs in winter, with natural nests having been found in February and March. Limited observations suggest that nests are attended by females (Beane et al. 2010; Stuart et al. 2020).

Clutch size is unknown, but probably comparable with other members of the E. bislineata complex. Stuart et al. (2020) reported a female containing 45 ova.

The length of the larval stage is unknown and probably variable and dependent on environmental factors. Larvae have been collected at all months of the year, indicating a larval period of at least one year (Stuart et al. 2020).

No data on the diet of larval Carolina Sandhills salamanders have been reported. They presumably feed on small invertebrates, as do other members of the E. bislineata complex (e.g., Smallwood, 1928; Burton, 1976). Large larvae in captivity have fed on small pieces of earthworms (Lumbricidae) (A. L. Braswell, pers. obs.).

Larvae occur in the same streams as adults and are commonly found in leaf beds, among mosses or rootlets, or in other vegetation or detritus (Stuart et al. 2020).

No larval polymorphisms are known and neoteny has not been observed (J. C. Beane per. obs).

Carolina Sandhills salamanders are semi-terrestrial. Adults and juveniles have been collected beneath sheltering objects and surface debris in and along blackwater streams and in adjacent floodplains and uplands (Stuart et al. 2020).

Torpor is unknown, but unlikely to occur. Winters are seldom severe within the species’ range, and adults are cold-tolerant and most often encountered in winter (J.C Beane per. obs).

Carolina Sandhills salamanders occur in springs and streams typically inhabited by several other salamander species, including lesser sirens (Siren intermedia), dwarf mudpuppies (Necturus punctatus), two-toed amphiumas (Amphiuma means), dusky salamanders (Desmognathus fuscus complex), Chamberlain’s dwarf salamanders (Eurycea chamberlaini), mud salamanders (Pseudotriton montanus), and red salamanders (P. ruber) (J. C. Beane per. obs).

Based solely on morphology, Stuart et al. (2020) reported putative hybrids between E. arenicola and E. cirrigera Lineage J of Kozak et al. (2006) in narrow areas of range overlap.

Diet and feeding behavior of adult Carolina Sandhills salamanders are poorly known, but they likely feed on a wide variety of small invertebrates, as do other members of the E. bislineata complex (e.g., Burton, 1976). A short-term captive accepted small earthworms (Lumbricidae) (J. C. Beane pers. obs.).

No predators have been reported, but it is easy to speculate that natural predators of both larvae and adults could include larger salamanders, fishes, crayfish, predaceous insects, large spiders, snakes, anurans, birds, and mammals. Many adults have been found killed by motor vehicles (J. C. Beane per. obs).

Trends and Threats
Carolina Sandhills salamanders have no special legal protection and are probably not in any immediate jeopardy. They appear to be relatively common throughout most of their known range. Protection of larval and adult habitats (springs and small streams and the adjacent forested uplands within the longleaf pine ecosystem) is important for the species' survival. Because of its small geographic range and regional endemism, this species has been designated as W3 Watch List (“species that is poorly known; perhaps needs listing in upcoming years”; LeGrand and Hall 1997) by the North Carolina Natural Heritage Program for more than 20 years (LeGrand and Hall 1997; Ratcliffe 2020).

Possible reasons for amphibian decline

General habitat alteration and loss

Comments
The species authority is: Stuart, B.L., Beamer, D.A., Farrington, H.L., Beane, J.C., Chek, D.L., Pusser, L.T., Som, H.E., Stephen, D.L., Sever, D.M., Braswell, A.L. (2020). "A new Two-lined Salamander (Eurycea bislineata Complex) from the sandhills of North Carolina." Herpetologica 76: 423-444

The specific epithet arenicola is taken from the Latin "arena" for "sandy place" and "cola" for "dweller" in reference to the species being restricted to the Sandhills of North Carolina, which is characterized by sandy soils, blackwater streams, and a Longleaf Pine ecosystem (Stuart et al. 2020).

This species was featured as News of the Week on 11 January 2021:

The Eurycea bislineata complex ("Two-lined salamanders") is found in eastern North America from Quebec to the Gulf of Mexico and as far west as the Mississippi River. Prior to 2020, the complex consisted of six species, but several studies have shown the potential for more species in the complex. The most recent molecular analyses by Stuart et al. (2020) identified a seventh new species, Eurycea arenicola, split from E. cirrigera. The new salamander is found in the Sandhills of North Carolina, where it had long been considered a distinct ecomorph or candidate for full species because of its unique orange to red color with black spots and its unique habitat. In the Carolina Sandhills, it lives in slow-moving blackwater streams rather than flowing rocky streams along with other endangered species of this restricted ecosystem of Longleaf Pine and wiregrass like the Pine Barrens treefrog (Hyla andersonii). Analyses by Stuart et al. also indicate a complex gene exchange history as the most closely related species in their mtDNA analysis were more distantly related in their nuclear DNA analysis and the most geographically close population was not closely related by either analysis. The Eurycea bislineata complex still has more answers to reveal, but this study helps our understanding of a decades long question (Written by Ann T. Chang).

References

Beane, J. C., A. L. Braswell, J. C. Mitchell, W. M. Palmer, Harrison III, J. R. (2010). Amphibians and Reptiles of the Carolinas and Virginia, 2nd Edition, Revised and Updated. University of North Carolina Press, Chapel Hill, North Carolina.

Burton, T. M. (1976). "An analysis of the feeding ecology of the salamanders (Amphibia: Urodela) of the Hubbard Brook Experimental Forest, New Hampshire." Journal of Herpetology, 10, 187–204.

Kozak, K. H., Blaine, R. A., Larson, A. (2006). "Gene lineages and eastern North American palaeodrainage basins: Phylogeography and speciation in salamanders of the Eurycea bislineata species complex." Molecular Ecology, 15, 191-207.

LeGrand, H. E., Jr., Hall, S. P. (1997). Natural Heritage Program List of the Rare Animal Species of North Carolina. North Carolina Natural Heritage Program, Raleigh, North Carolina.

Ratcliffe, J. (2020). Natural Heritage Program List of the Rare Animal Species of North Carolina. North Carolina Natural Heritage Program, Raleigh, North Carolina.

Smallwood, W. M. (1928). "Notes on the food of some Onondaga Urodela." Copeia, 169, 89–98.

Stuart, B.L., Beamer, D.A., Farrington, H.L., Beane, J.C., Chek, D.L., Pusser, L.T., Som, H.E., Stephan, D.L., Sever, D.M., Braswell, A.L. (2020). "A new Two-lined Salamander (Eurycea bislineata Complex) from the sandhills of North Carolina." Herpetologica, 76(4), 423-444. [link]

Species Account Citation: AmphibiaWeb 2021 Eurycea arenicola: Carolina Sandhills Salamander <https://amphibiaweb.org/species/9303> University of California, Berkeley, CA, USA. Accessed Dec 1, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 1 Dec 2024.

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