Thornback rays inhabit waters off the Pacific coast from San Francisco to Baja California. They are also the most common ray off European shores from Norway to the Mediterranean. They prefer sand-covered or muddy areas.
Appearance is skate-like, with a brown upper body and white underside.
The head is rounded. Thornbacks grow up to three feet in length. They have rough skin with rows of thorny spines on the tail and back, and many large thorns on the wings. Females are often more spiny than males. Thornback rays eat shrimp, fish and crustaceans.