Found throughout the eastern Atlantic Ocean in sediment such as mud or sand and in shallow water no deeper than 60m. Found as far south as South Africa, the cosmopolitan thornback ray (Raja clavata) is common in the waters of Liverpool Bay. Growing up to a 1.3m in length, this ray earns its common name from the thorn like spines found down the centre of its body and its tail and further across their body as they age, even on the underside in females. They are commonly sandy brown in colour and have white spots across their backs. The oviparous thornback lays up to 160 eggs each year and these eggs, known as mermaids purses (similar to those of the small spotted and greater spotted catsharks, but are noticeably wider) are often found on beaches around Liverpool Bay suggesting the animals commonly breed in our local waters.
IUCN status Near Threatened.
The thornback is an important commercial species and in much of its range, it is also commonly caught as bycatch and in recent years has led to the decline of this species. Due the size of this ray, they are unable to escape nets when caught and are often killed when caught. With slow growth rates and low fecundity, fisheries have become a serious threat to this species.
Thornback rays feed on a wide range of species from crustaceans to fish. Juveniles primarily feeding on small crustaceans such as amphipods and small shrimp. The adult diet widening to include large crustaceans and small fish species.
Where to find them:
Thornbacks rays are commonly found throughout the Irish sea and Liverpool Bay’s sandy seabed is ideal habitat for them. In the November they are known to be found in large numbers in the River Mersey, though the reason for this is as yet unknown. Mermaids purses are also commonly found on the beaches across Liverpool Bay.
Did you know that rays and sharks form a group called elasmobranchs and the major difference between the two is the location of their gills? In sharks gills are on the side of their body, in rays they are on the underside.