This small box settled under river side boulders is aimed to catch delicate loach, Niwaella delicata. In autumn, this loaches migrate from stream riffles to stream bank underground water for wintering and spawning. Because of their hard to be seen feature, large part of their spawning ecology in the field is still unknown.
The box is traditional fishing gear using their such feature. It is said that the right of setting this box is allowed for only few peoples in the village for wise use.
In the mountain, I’m sometimes surprised at the mountain people’s knowledge about fishes.
