Thornback Ray 7669343154 O
7Identifcation number on The Map®

Thornback Ray

Platyrhinoidis triseriata

Thornback RayAshley Brock


  • Rounded disc slightly wider than long with rounded anterior edge which has a thin white margin
  • Three pronounced rows of tubercles (spines) run along back and tail from behind eyes
  • Tail broad with two well developed, rounded dorsal fins of roughly equal size set close to caudal fin
  • Oval caudal fin small
  • Dorsum uniformly light brown to grey
  • Ventrum pale
  • Two separate rostral cartilages extend from the skull to the tip of the snout which differentiates thornback rays from guitarfishes which have only one


  • Common southern California; occasional to uncommon central California


  • The thornback ray is usually found on sediment type seabeds such as mud, sand or gravel at depths between 10-60 m


  • Juvenile fish feed on small crustaceans, particularly amphipods and bottom-living shrimps – adults feed on crabs, shrimps and small fish

Interesting Facts

  • Morphologically thornback rays fall somewhere between guitarfishes and torpedo rays and may represent the evolutionary link between the two families