Development of LAMP primers for rapid detection of invasive smallmouth bass from environmental DNA

The smallmouth bass Micropterus dolomieu is a major invasive alien species and has a tremendous negative impact on natural aquatic ecosystems around the world. To prevent its range expansion, early detection and countermeasures are critical. Here, we have developed a primer set that can specifically detect smallmouth bass from environmental DNA (eDNA) using only isothermal reactions by the loop-mediated isothermal amplification (LAMP) method. This primer set was applied to DNA samples from tissues of M. dolomieu, M. nigricans, and Lepomis macrochirus to confirm specificity, and positive reactions indicated by white precipitates were obtained only for samples from smallmouth bass. Furthermore, tests using an eDNA sample obtained from the water of the Kinu River in Japan, where smallmouth bass inhabit, also yielded a positive result, indicating its applicability to eDNA. This primer set will be useful for the early detection of the introduction and range expansion of this species and contribute to stream management.