First records of Tanakia lanceolata from the Kita River System in Fukui, Japan in 45 years

In 2024, two individuals of Tanakia lanceolata were collected from the Kita River System in Fukui Prefecture, Japan. Previously, only a single specimen of T. lanceolata had been recorded from this river system, collected in 1979. This report thus represents the first specimen-based record from the river system in 45 years. Furthermore, mitochondrial DNA analysis was conducted on the collected individuals. The results showed that the specimens belong to a group naturally distributed from Ishikawa Prefecture to Kyoto Prefecture and did not match any previously reported haplotypes. These findings suggest that a native population has persisted in the Kita River System without extinction and should be considered for conservation.