Thornback Ray

The Thornback Ray (Raja clavata) is one of the most widespread and commonly encountered skates in European waters, belonging to the family Rajidae. It takes its name from the prominent rows of large, hooked thorny spines that cover its back, tail, and sometimes underside, especially in females and larger individuals. Found from the North Sea and British Isles south through the Mediterranean and along the West African coast, it is a familiar species to anglers and is frequently caught in mixed demersal fisheries. While still relatively common compared to some larger skate relatives, its populations have declined in some heavily fished areas, and it is monitored as Near Threatened in parts of its range.

• Disc: rhomboid, with a moderately pointed snout and rounded wing edges
• Color: variable mottled brown, tan, or grey above with darker blotches and scattered pale spots
• Spines: distinctive rows of large, curved thorny spines along the midline of the back and tail
• Underside: pale cream to white, generally smooth
• Size: typically 70-105 cm total length

The heavy covering of large thorns, especially the prominent row down the back and tail, readily distinguishes it from smoother-skinned skates such as the little skate.

Thornback Rays occur widely across the northeastern Atlantic, from Norway and the British Isles south through the Bay of Biscay, Mediterranean Sea, and along the coast of West Africa. They inhabit sandy, muddy, and mixed sediment seabeds from shallow inshore waters, including estuaries, down to depths of around 300 m, though they are most commonly encountered on the continental shelf at moderate depths. Juveniles often use shallower coastal nursery areas, while larger adults range into deeper offshore waters, with some seasonal inshore-offshore movement linked to breeding.

Thornback Rays are bottom-dwelling predators that lie partly buried in sediment, ambushing crustaceans, small fish, and other invertebrates that pass nearby. They are generally solitary but can be locally abundant on productive fishing grounds. Reproduction is oviparous, with females laying distinctive horn-shaped egg cases equipped with curling tendrils that anchor them to the seabed; these cases take several months to over a year to hatch depending on temperature. The prominent thorns are thought to provide some defense against predators and may play a role in interactions between individuals during the breeding season.