Emergence of Potamogeton lucens, a Critically Endangered Aquatic Species, at a Newly Constructed Flood-control Reservoir in Tochigi Prefecture, Japan

Abstract

A critically endangered aquatic species, Potamogeton lucens (Potamogetonaceae), was discovered in a newly constructed flood-control reservoir adjacent to the Gogyo River in Tochigi Prefecture, Japan. Morphological observation and DNA sequencing were performed to identify the species. The plant likely re-emerged from seeds buried in the soil. The site at which the reservoir was constructed had previously been a paddy field since at least 1961, and it has been hypothesized that P. lucens seeds can remain dormant in the soil for several decades. In addition, many other aquatic species have appeared, including Potamogeton wrightii, Stuckenia pectinata (Potamogetonaceae), Najas chinensis and Ottelia alismoides (Hydrocharitaceae). These results indicate the potential of flood-control reservoirs as habitats for aquatic plants, emphasizing their importance in the regeneration and conservation of aquatic plant diversity.