Black sawtail cranes mainly eat seaweed and benthic organisms. Black saw-tailed cranes basically live in coral-clustered reef areas, usually in groups. The largest black saw-tailed crane is 50cm long.

The whole body of black sawtails is gray or nearly Black, there is a certain difference in body color between the young black sawtail and the adult black sawtail. The body of the young black sawtail is brown-red as a whole. The spinous groove of the tail handle is black, the rear edge of the caudal fin of the black saw-tail hanging fish is white, and the body of the young black saw-tail hanging fish is uniformly brown-red, and the rear half of the tail handle to the entire caudal fin is white.