
The Doubleheader can be recognised by its colouration and the prominent bump that develops on the head of both males and females.
The fish in the image shows a typical colour pattern. It is blue-grey with a large blackish area covering the entire caudal peduncle.
This species grows to 60cm in length.
It is known from northern New South Wales, Elizabeth and Middleton Reefs, Lord Howe Island, and Norfolk Island.
View a map of the collecting localities of specimens in the Australian Museum Fish Collection.