eDNA Monitoring of a Rare Salamander: the Use of eDNA in Detection of Eurycea junaluska in the Great Smoky Mountains National Park, USA
Brammell BF, Brewer SA, Strasko EK, Cox MM, Johnson JR, Peyton DK. 2025. eDNA Monitoring of a Rare Salamander: the Use of eDNA in Detection of Eurycea junaluska in the Great Smoky Mountains National Park, USA. Herpetological Conservation and Biology. 20(3):550-570
ABSTRACT: The Junaluska Salamander (Eurycea junaluska) is a small, semiaquatic plethodontid salamander with a restricted range, much of which is encompassed within the Great Smoky Mountains National Park (GSMNP). Eurycea junaluska was first described in 1976 and is known to exist in only five counties in a small area of Tennessee and North Carolina. Environmental DNA (eDNA) is an emerging tool that promises to greatly increase the ease, efficacy, and scope of ecological studies. The objectives of this study were to develop and validate a species-specific assay that detects E. junaluska and to utilize this assay to reassess the distribution of E. junaluska within the boundaries of the GSMNP. We sequenced a portion of the mitochondrial gene cytochrome b (cytb) from E. junaluska and sympatric salamander species, designed a qPCR assay for E. junaluska detection, and confirmed the specificity of this assay in silico and in vitro against all other salamander species found in the GSMNP and two additional Eurycea species. We collected 50 water samples from 30 of 46 U.S. Geological Survey hierarchal hydrologic unit code 12-digit sub-watersheds found within the GSMNP, including all major watersheds. We collected water samples in first to sixth order streams, and we used the developed qPCR assay to detect E. junaluska eDNA in the extracted water samples. Target DNA was detected at four sites, all in large, low-elevation, relatively low-gradient streams, each with extensive historic observation records of E. junaluska. Occupancy modeling indicated a low probability of false positive, but a somewhat higher probability of false negative, errors as well as the significance of covariates influencing the probability of E. junaluska detection including elevation, Strahler stream order, and location of the site within the GSMNP.
- Type
- Journal Article
- Authors
- Brammell, Ben; Brewer, Sara; Strasko, Elizabeth; Cox, Madeline; Johnson, Jarrett; Peyton, David
- Units
- GRSM
- Keywords
- Amphibia, Caudata, eDNA occupancy modeling, environmental DNA, Eurycea junaluska, GRSM-01193, Junaluska Salamander, Salamanders, single-species eDNA assay