Covered in large sharp thorns and carrying no venomous barb at all, which is unusual in the family and worth knowing.
To about 1.5 m across the disc, thick, round, sandy grey, and covered in large sharp conical thorns over the back and tail. Those thorns are the identification and they are unmistakable.
It has no venomous barb at all, which is unusual in the family and worth knowing: the thorns are the whole of its defence and they are mechanical rather than venomous. It lies on sand in lagoons and on reef flats in the Maldives and across the Indo-Pacific, feeding on buried invertebrates. It is uncommon and listed as vulnerable.
Ratings are per location: 1 means found on most dives that look for it, 5 means a handful of records. Where enough dives have been logged the figure is calculated from them; otherwise it is an editorial estimate, and says so. We publish habitat and destination, not the dive site.