Raja clavata (Linnaeus, 1758)

Roker, Thornback Ray

Raja clavata

Description: The thornback ray is probably one of the commonest rays encountered by divers. Like all rays it has a flattened body with broad, wing-like pectoral fins. The body is kite-shaped with a long, thorny tail. The back is covered in numerous thorny spines. In sexually mature fish some of the spines are thickened with button-like bases (known as bucklers). These are particularly well developed on the tail and back of sexually mature females. The colour varies from light brown to grey with darker blotches and numerous small darker spots and yellow patches. Sometimes the yellow patches are surrounded by small dark spots. The underside is creamy-white with a greyish margin. Adult fish can grow to 1m in length although most are less than 85cm.

Habitat: The thornback ray is usually found on sediment type seabeds such as mud, sand or gravel at depths between 10-60m. Juvenile fish feed on small crustaceans, particularly amphipods and bottom-living shrimps, Adults feed on crabs, shrimps and small fish.

Distribution: This species is common all around the coasts of Britain and Ireland.

Similar Species: Other rays have spiny thorns, especially on their tails however only the thornback has large spines with button-like bases (bucklers).

Key Identification Features:

• Thorny back
• Numerous thorny spines with broad bases
• Yellow patches on back, sometimes encircled by dark spots

Distribution Map: NBN map : National Biodiversity Network mapping facility, data for UK.

WoRMS: Species record : World Register of Marine Species.

iNaturalist: Species account : iNaturalist World Species Observations database