The edge is hanging, the whole body of the fish is dark brown, with many blue round spots on the head, pectoral fin and body side, and blue thin horizontal stripes on the dorsal fin, anal fin and caudal fin.

Yuandai lives in the climate zone between 15 degrees north latitude and 25 degrees south latitude At the same time, since it has not yet been explored what the eating habits of the danglings are, it is mainly inferred that they feed on algae. They prefer to inhabit shallow coral reef areas with water depths between 2-18 meters. Usually solitary, but also in small groups in rapids in surge zones.