Circular Stingaree, Urolophus circularis

The circular stingaree (Urolophus circularis) is a little-known and uncommon species of ray unique to southwestern Australia. Its habitat ranges from rocky bottoms to reefs and sea floors with vegetation. It can be found close to shore as well as at depths of up to 390 feet.

Very little information exists on the circular stingaree with only a handful being displayed in museums and few are caught by trawlers because of the terrain it resides in. They are listed by the International Union for Conservation of Nature as least concern.

The disc of the circular stingaree is almost a circle being nearly as wide as it is long. The large mouth slightly extends from the disc and contains ten nipple-shaped structures on the lower jaw and small oval-shaped teeth. Behind the large eyes are comma-shaped air holes and between the nostrils is a short skirt-shaped layer of skin that extends into lobes. It also has five pairs of short gill slits. It can grow up to 24 inches long.

The tail is about two thirds as long as the disc and is oval in shape at the base and progresses to a short leaf-shaped tail fin. On the tail is a large dorsal fin with a serrated stinging spine directly behind. It has smooth skin that is normally slate-blue with many whitish colored spots, blotches and rings with white bordered large black spots formed in a ring on the center of the disc. The dorsal fin and tail fin’s margin may be of a brown shade and the underside is plain white, turning a light brown on the tail.

Image Caption: Circular stingaree (Urolophus circularis). Credit: Clay Bryce/Wikipedia (CC BY-SA 3.0)