Head to head
Thornback Ray vs Small-spotted Catshark
Thornback Ray
VS Small-spotted Catshark
The thornback ray and the small-spotted catshark are two of the commonest cartilaginous fish of European coasts, and the empty egg cases of both end up on beaches as mermaid's purses.
| Thornback Ray | Small-spotted Catshark | |
|---|---|---|
| Scientific name | Raja clavata | Scyliorhinus canicula |
| Group | A ray, with a flat, diamond-shaped body | A shark, with a slim body and a pale underside |
| Size | Usually 60 to 85 cm long, though larger fish occur | Usually around 60 to 80 cm in length, one of the smallest sharks of European waters |
| Skin and colour | Brown to grey with pale blotches, with a back and tail studded with prickly thorns | Sandy brown with many small dark spots and a few larger blotches, with rough skin that feels like sandpaper |
| Egg cases | Lays tough, rectangular egg cases with a horn at each corner | Lays tough, oblong egg cases with curly tendrils at each corner that anchor them to seaweed |
| Diet | Crabs, shrimps, worms, and small fish found on the sand and mud of the sea bed | Crabs, shrimps, molluscs, worms, and small fish, found mostly at night |
| Behaviour | Lies half buried on sandy and muddy sea beds, with only its eyes and tail visible | Rests on the bottom or in caves and crevices by day, and becomes more active at night |
| Conservation status | Near Threatened, because it matures late, has few young, and has been heavily fished in parts of its range | Least Concern, widespread and abundant, and sometimes sold in the UK as rock salmon |
Thornback Ray vs Small-spotted Catshark: common questions
Which one is a shark?
The small-spotted catshark is a shark, while the thornback ray is a ray with a flat, diamond-shaped body.
What is a mermaid's purse?
It is the tough egg case of a ray or shark, and both the thornback ray and the small-spotted catshark lay them.
Which one is threatened?
The thornback ray, which is Near Threatened because it matures late, has few young, and has been heavily fished in parts of its range.