15. The Thornback Ray (Raja Clavata) Wildlife of the Solway
Wildlife of the Solway Firth – The Thornback Ray by Mark Vollers
The relatively shallow waters of the Solway Firth provide ideal living conditions for several species of Rays, of which the most common at present is probably the Thornback.
These fish are closely related to sharks, being cartilaginous, but are flattened laterally ( as if squashed from above) and their ventral fins have become massively enlarged and fused the length of their body to give the characteristic diamond shape.
The gills have special openings ( known as spiracles) that are handily placed at the highest point of the body so that the fish can breathe whilst shuffled down into the sand or mud of the sea-bed, and the eyes are raised up to give 360 degree vision.
Their low frontal profile allows them to pounce swiftly on their prey. Rays and Skates are part of the same family ( along with Spotted, Small eyed, Cuckoo and Undulate ‘Rays’) and have characteristic spines or thorns along their backs.
They produce young by laying egg cases or ‘Mermaids purses’ which are left by the mother to hatch after several months into perfect mini-skates which are totally self sufficient. They can take up to a decade to reach maturity and lay relatively few eggs a year thereafter.
Not surprising then that commercial fishing has totally eliminated a near relative of the thornback, the Common Skate, in English and Welsh waters in the last 30 years. To help prevent this happening to other species only buy large size ‘ skate wings’ from your fishmonger…these fish should have at least had a chance to breed.
Rays are endlessly popular exhibits in the Lake District Coast Aquarium at Maryport because their natural curiosity and placid nature allows them to be gently stroked by visitors…no other fish we have would tolerate this. At feeding time we ensure that all visitors have taken their fingers out of the water as they could easily be mistaken by the fish as something tasty!