Abstract
The status of the endangered Japanese eight-barbel loach Lefua echigonia in the Naka-ikemi Wetland, Fukui Prefecture, officially registered as a sanctuary at the Ramsar Convention 2012, was surveyed from October 2010 to August 2012. The loach population, comprising approximately 300 individuals, was restricted to a small spring covering an area of only 84 m2, a fraction of the total wetland area (250,000 m2). The size frequency distribution of the collected individuals showed bimodal peaks in May to August, and showed a unimodal peak in April, September and October. The loach population is considered highly vulnerable and in need of significant protective measures.
