Description

DESCRIPTION:

Aneides caryaensis is a moderate-size salamander species with a slender, flattened body. The standard length of males ranges from 48.5 - 58.4 mm and female range from 52.8 - 59.8 mm. The heads are relatively broad and strongly flattened, with a head width of 10.01 ± 0.83 mm and a mean snout gular length of 14.07 ± 0.79 mm. The adductor muscles of their jaws bulge out behind their large, prominent eyes, and is slightly more pronounced in males than in females. Maxillary teeth in these species are in short rows and the posterior portion of maxillary bone lacks teeth. The distance between the axilla to groin has a mean length of 27.16 ± 4.27 mm. The mean forelimb lengths are 16.21 ± 1.09 mm, the mean hindlimb lengths are 18.84 ± 1.09 mm, and when adpressed the limbs overlap by 2.5 - 4.0 costal interspaces. They have very long legs of moderate size and very long digits. They also have slender, whip-like tails that range in proportion from 0.93 - 1.07 of the standard length. They have a mean tail length of 56.08 ± 5.45 mm (Patton et al. 2019).

DIAGNOSIS:

Aneides caryaensis is morphologically cryptic to members of the subgenus Castaneides, which includes A. aeneus. But, A. caryaensis and A. aeneus display subtle coloration differences and relative size differences. Specifically, A. caryaensis has smaller and more disconnected pigmented areas and lack of dark pigmentation on its flanks. Additionally, A. caryaensis has a broader and longer head, broader shoulders, broader feet, longer toes, and more maxillary and pre-maxillary teeth. Like other Aneides, the premaxillary teeth are slightly larger than other plethodontids (Patton et al. 2019).

COLORATION:

In life, the ground color of the dorsal surfaces is dark brownish-black and the dorsum is covered by patches of bright green to yellowish-green pigment that look like lichen. The flanks have a light grayish-yellow ground coloring. The ventrum is paler than the dorsum with a loose suffusion of melanophores that decrease in density toward the midline (Patton et al. 2019).

VARIATION:

The only potential instances of sexual dimorphism noted in this species are the teeth number and jaw muscle size: Females have a somewhat higher tooth number and males have slightly larger jaw muscles. In males, the premaxillary teeth penetrate the upper lip (Patton et al. 2019).

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.

Aneides caryaensis can be found in Hickory Nut Gorge, in the vicinity of the town of Bat Cave, in both Henderson and Rutherford Counties, North Carolina, United States. To be precise, the holotype was collected in warm, fair, and moist conditions from a tight rock crevice in the late afternoon. Other individuals were also found on rocky outcrops (Patton et al. 2019).

Life History, Abundance, Activity, and Special Behaviors
Aneides caryaensis is a rocky outcrop specialist (Patton et al. 2019).

Aneides caryaensis was recently split from A. aeneus, based on several lines of evidence. Unfortunately, although there is a possibility that its ecology is similar to A. aeneus, few studies have verified the assumption and little is known about the ecology of A. caryaensis (Patton et al. 2019).

Unlike Plethodon yonahlossee, which is also found in the same area, when tickled, A. caryaensis, will flatten against rocks and hold tight. Plethodon yonahlossee will drop off when tickled (Patton et al. 2019).

In addition to Plethodon yonahlossee, A. caryaensis also co-occurs with Plethodon amplus and Desmognathus cf. carolinensis, however, the last species could actually be an intergraded population with Desmognathus ocoee (Patton et al. 2019).

Trends and Threats
Aneides caryaensis is habitat specialist that occupies a very narrow range, with only 25 localities. Despite extensive surveys, the species is rarely found and the population status is unknown. As a result, it is especially vulnerable to habitat loss and fragmentation. They are primarily threatened by growing real estate and tourism development, as well as transportation and energy infrastructure in the area. The species also shows evidence of inbreeding and is likely susceptible to all the risks associated with small population sizes (Patton et al. 2019).

Conservation measures that could help the species include protecting known and potential sites where the species lives from logging, development, and collecting, along with buffers around those sites. Because of the genetic distinctiveness for the species, it is also likely an evolutionary significant unit and should be listed under the United States Endangered Species Act. However, more evidence needed to support this (Patton et al. 2019).

Possible reasons for amphibian decline

General habitat alteration and loss
Habitat modification from deforestation, or logging related activities
Urbanization
Habitat fragmentation
Loss of genetic diversity from small population phenomena
Intentional mortality (over-harvesting, pet trade or collecting)

Comments

PHYLOGENETIC RELATIONSHIPS:

Aneides caryaensis is closely related to A. aeneus, and was previously thought to be a population of A. aeneus. They were split based on morphology and genetic data, including microsatellites, mtDNA, and nDNA. Bayesian analysis on Cytochrome b and 12S rDNA sequences indicate that A. caryaensis is most closely related to the clade composed of Northern Appalachian and Blue Ridge Escarpment populations of A. aeneus with Southern Appalachian populations of A. aeneus populations being the next most closely related. Those populations may be split into other species in the future. The molecular clock for this phylogeny indicates that the most recent common ancestor between A. caryaensis and all other lineages within the A. aeneus complex is estimated to have been around 11 MYA (Patton et al. 2019).

Aneides caryaensis is grouped within the genus Aneides, with members of the subgenus Castaneides (Patton et al. 2019).

ETYMOLOGY:

The species was named after the Hickory Nut Gorge of Western North Carolina where it lives. The researchers allude to this area in the species epithet, “caryaensis” by referencing the Hickory genus, Carya, after which the area is named (Patton et al. 2019).

Hickory Nut Gorge has several species that are genetically or morphological unique to the Gorge. It is unclear what mechanism resulted in this diversification (Patton et al. 2019).

References

Patton, A., Apodaca, J. J., Corser, J. D., Wilson, C. R., Williams, L. A., Cameron, A. D., Wake, D. B. (2019). "A new green salamander in the southern Appalachians: Evolutionary history of Aneides aeneus and implications for management and conservation with the description of a cryptic microendemic species." Copeia 107(4):748-763. [link]

Species Account Citation: AmphibiaWeb 2022 Aneides caryaensis: Hickory Nut Gorge Green Salamander <https://amphibiaweb.org/species/9112> University of California, Berkeley, CA, USA. Accessed Apr 19, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 19 Apr 2024.

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