Thornback Ray

Thornback Ray

    • Scientific name: Raja clavata
    • Also know as: Roker, Skate, Thornback Skate
    • Size: Up to 4ft (from wingtip to wingtip) and 35lbs (UK shore caught typically 2-12lbs)
    • UK minimum size: 16inches (41cm) from wingtip to wingtip
    • UK shore caught record: 22lb 11oz
    • IUCN Status: NT (Near Threatened)
    • Distribution: Found around the UK and Ireland on clear sandy, muddy and shingle seabeds and in clear sections of ground in the middle of rocky areas. Can be scarce along much of the east coast of Scotland and England.
    • Feeds on: Crustaceans and crabs mainly, but will also eat small fish, especially flatfish.
    • Description: Kite shaped with a long tail. Light orange/brown marbled pattern on the back, with pale spots covering the body. The central part of the body covered in horns and spikes, which grow to the edges of the rays as they get older. Mature females may also have thorns on the underside, which is white/pale. Other species of ray may also have thorns (making identification confusing) but thornback ray have the most of any species.

Thornback ray is a highly prized catch for the shore angler, with many anglers happy to put great time and effort into fishing for this species. Thornback rays generally stay in water under one hundred metres deep, and in summer they will come into even shallower inshore water and within the range of sea anglers. Thornback rays mostly feed once the sun has started to set, spending daylight hours partially buried in the sand. The type of seabed is important when it comes to thornback ray fishing. This species prefers sandy or shingle ground, usually next to rocky outcrops, or where the seabed is broken up with stones and weeds. Ground where sand, single and/or mud intermix can also hold rays. Like most species, thornback ray are attracted to gullies and other features which are likely to hold sources of food. A totally flat and featureless seabed is unlikely to attract any rays. Anglers who regularly catch thornback ray often know the location of undersea features which attract thornback ray, although they will often keep this information to themselves. Thornback ray are not particularly fussy eaters and will scour the seabed looking for food. They have a relatively small mouth, but their jaws are powerful enough to crunch through the shellfish and crabs that make up the majority of their diet. They will also eat other small fish, especially flatfish that they are likely to come across. Thornback ray tend to lie in wait and ambush other fish, rather than actively hunt and pursue them. This species is thought to have a lifespan of up to fifteen years.

Conservation Status and Commercial Value

Underside of thornback ray
The underside of a thornback ray showing the mouth and nasal openings.

The International Union for Conservation of Nature states that the thornback ray is Near Threatened with a decreasing population trend. However, in certain parts of the UK (the southern North Sea, west of Scotland and Ireland) populations of this thornback ray appear to have stabilised. Until 2008 commercial trawlers were not required to differentiate between different species of ray and could bundle all of these species together in a generic ‘skates and rays’ category which made it difficult to assess how the numbers of different ray species were holding up. The changes in this area should allow better and more accurate stock assessments to be made. Like all ray species thornbacks are extremely vulnerable to overfishing for a number of reasons. They are a slow-growing and late-maturing species meaning that stocks take a long time to recover from overfishing, and the fact that thornback ray form into shoals means that a whole group can be wiped out by a single trawler in a short period of time.

Rays have value to commercial fisheries and are taken for human consumption, although a lot of thornback rays taken by commercial vessels are bycatch which may be discarded at sea. Anglers can do their part in protecting thornback ray numbers by releasing any rays caught on a rod and line.

Methods and Techniques to Catch Thornback Ray

Ray do not come particularly close to the shore as they are aware that they can get trapped in shallow water by the retreating tide. This means it can be necessary to cast long distances to be in with a chance of catching a ray. For this reason clipped down rigs are used to gain extra distance. Hook size 1/0 – 3/0 would be appropriate with a heavy gauge pattern used to handle the ray’s crushing plates, although thornback rays have a relatively small mouth, so hooks should not be any larger than this.

Long and Low Rig
The long and low rig clipped down for casting (left) and with the hook released (right). This rig uses a bait clip to clip the extra-long hooklength up meaning the rig can be cast without becoming tangled. However, once the rig has settled on the seabed the hook will be a good distance away from the weight, meaning rays will not spike themselves on a grip weight if one is used.

Many anglers are cautious of using grip weights when fishing for thornback ray, believing that when a ray settles onto a bait they will be effectively spiked by the grip weight wires and swim away. This can be avoided by only using plain weights, or, if fishing in a strong tidal flow where grip leads are needed, fishing with extra-long snoods so that the bait and hook settles a long distance from the weight. The long and low rig (also known as the up and under rig) is an excellent way of presenting a bait for thornback ray as the rig incorporates an extra-long snood and can still be cast a long distance without tangling. Read more about how to make this rig by clicking here.

Use caution when removing hooks from the powerful mouth of a thornback ray, it is best to use pliers or a disgorger – such as the Koike disgorger which is available from Sea Angling Shop for only £3.19. Anglers should also be careful when picking up a thornback ray for a photo as well as the thorns on the back can pierce skin meaning it is best to wear a pair of thick gloves when handling thornback rays. Fish baits such as mackerel fillet, bluey, sandeel or herring are good baits for ray, while in spring peeler crabs can have the most success. Later in the year combinations of rag, lugworm and squid can all catch this species. Thornback ray can sometimes move around in shoals, meaning that once one has been caught others can follow.