The Blue Gudgeon Dartfish (Ptereleotris hanae) is also known as the Threadfin Dart Goby. They can be found among the Indo-Pacific ocean, off the coasts of Indonesia and Japan. They frequently live in pairs among lagoons or flats with long stretches of sand where they can burrow into. They feed on small crustaceans and zooplankton, and should be kept in an established tank with plenty of room to swim. They also require the thick sand bed to hide among, and should have a good amount of live rock. Dartfish are peaceful fish and should be housed with tankmates of similar temperament. They are notorious for jumping, so a tight lid should be kept on the aquarium at all times.