Thornback ray (Raja clavata)
The thornback ray is a medium-sized ray, with thorns running in a row from its head down along its back and along its tail; adult thornbacks have many thorny knobs called ‘bucklers’ scattered along their dorsal surfaces. Thornbacks are nocturnal animals, inhabiting muddy, sandy or gravelly seabeds and feeding on crustaceans and small fish. The thornback ray is oviparous, with females laying an estimated 60-140 eggs per year. Juveniles tend to remain inshore after hatching, whereas adults migrate inshore from deeper waters to breed spring and summer.
The conservation status of the thornback ray is listed as least concern on Irish Red List for cartilaginous fish and by the IUCN Red List. Thornback ray are frequently a bycatch for commercial trawl and gillnet fisheries. In Irish waters, however, the thornback population appears to be growing.
The Marine Sportfish Tagging Programme tagged 9,082 thornback ray between 1970 and 2009 were tagged off the coast of Ireland, with hotspots at Tralee Bay, the Shannon Estuary, Clew Bay and Dingle. Thornbacks tend not to travel far, and 79% of recaptures were within 10km of their original tagging location.
