Abstract Objective To enhance monitoring efforts and provide new insights into the population status and ecology of the Rio Grande Silvery Minnow Hybognathus amarus, we designed two sets of hydrolysis probe quantitative real-time PCR assays to be combined with environmental DNA (eDNA) sampling to provide a noninvasive method for detecting this endangered species. Methods Each assay was validated with eDNA samples that were collected from (1) tanks holding Rio Grande Silvery Minnow, (2) locations that the species is known to occupy within the middle Rio Grande (New Mexico, United States), and (3) locations where the species is presumed to be absent in New Mexico. Results Both quantitative real-time PCR assays are highly sensitive, with limits of detection at two and eight copies of target DNA per reaction. Tandem use of the two assays increases detection power and reduces the risk of false negative results. Conclusions Our newly developed noninvasive eDNA tool for the detection of Rio Grande Silvery Minnow will support recovery efforts and adaptive management by augmenting the current methods that are used to monitor the population status and distribution of the species.
Lindsay et al. (Tue,) studied this question.