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ABSTRACT The Indo‐Pacific lionfish,Pterois volitans,is an invasive species in the western Atlantic. Since its introduction to Florida in the early 1980s, populations have surged with lionfish now found from North Carolina to Venezuela. As their range expands, these generalist predators threaten native fauna, and while they are primarily a marine species, their tolerance for low salinity conditions may allow them to expand into sensitive estuarine habitats undetected. Traditional approaches for tracking invasive species such as direct observation or trapping are impractical over large spatial scales, making environmental DNA (eDNA) an attractive alternative. Molecular assays, such as those employing quantitative polymerase chain reaction (qPCR), amplify low copy number DNA fragments in environmental samples and are increasingly employed as a complement to traditional methods for the detection of invasive species. Currently, there is one published PCR assay for the detection of lionfish eDNA. However, the specificity of this assay is unverified, and the critical performance parameters limit of detection (LOD) and limit of quantification (LOQ) have not been established. Here we evaluate the efficacy of this assay and show that it is likely to result in false negatives in the western Atlantic. As an alternative, we developed a new TaqMan probe‐based qPCR assay that is species‐specific forP. volitansand highly sensitive with a LOD of 12 copies per reaction and a LOQ of 598 copies per reaction. While our assay does not amplify the closely relatedP. miles, which was also introduced in the western Atlantic, the low prevalence of this species in the invasive population means our assay is effective for most monitoring purposes. We conclude that our assay is a robust method for the detection of lionfish and can be employed in any habitat, offering new opportunities for controlling the spread of invasive lionfish.
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Using Environmental DNA Sampling for Simultaneous Detection of Hosts and Their Pathogens: A Case Study With the Critically Endangered Frog Genus Atelopus
ABSTRACT Studying declining and rare species is inherently challenging, particularly when the cause of rarity is emerging infectious diseases (EIDs). Tracking changes in the distribution of pathogens that cause EIDs, and the species made scarce by them, is necessary for conservation efforts, but it is often a time and resource intensive task. Here, we demonstrate how using environmental DNA (eDNA) to detect rare species—and the pathogens that threaten them—can be a powerful tool to understand disease dynamics and develop effective conservation strategies. Amphibian populations around the world have undergone rapid declines and extinctions due to the emerging fungal pathogen,Batrachochytrium dendrobatidis(Bd). We developed and validated a qPCR assay using eDNA sampling methods for some of the most imperiled amphibian species, harlequin frogs (Atelopus varius,Atelopus zeteki,andAtelopus chiriquiensis), and applied this assay in concert with a standard qPCR assay forBdin rainforest streams of Panamá. We confirmed the presence ofAtelopusat sampling locations across three regions. In addition, we used genomic analysis of eDNA samples to show thatBdin Panamá falls within the Global Panzootic Lineage, a lineage associated with disease‐induced declines. We detectedBdDNA in most of our historic sites, and its concentration in water samples correlated with stream characteristics and the pathogen load of the local amphibian community. These results suggest that some populations ofAtelopuspersist in their historic localities. They also show how eDNA analysis can be effectively used for monitoring species presence, pathogen concentrations, and the distribution and spread of pathogen lineages. EIDs are a growing threat to endangered species around the world. Simultaneous detection of rare and declining host species and their pathogens with eDNA will help to provide key insights for effective conservation management.
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- PAR ID:
- 10592606
- Publisher / Repository:
- Animal Conservation
- Date Published:
- Journal Name:
- Animal Conservation
- ISSN:
- 1367-9430
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript
- Journal Article:
- https://doi.org/10.1111/acv.13012
