From the waters of Japan comes Lefua nikkonis, a member of the family Nemacheilidae. A sand-sifting bottom resident most active after the lights fade. It lives on the bottom. Adults reach 6–8.8 cm. Loose groups of 5+; loneliness makes them shy. Choose sand over gravel, feed after dusk, and keep ammonia at zero — loaches punish neglect visibly. Maintain 15–25 °C at pH 6.8–7.5. Undemanding once its core needs are met.