Question: Are catsharks the only oviparus group of sharks that inhabit waters around the UK?

Lesser-Spotted Catshark answered on 9 Nov 2017:

Yes they are! Both the lesser-spotted catshark (Scyliorhinus canicula) and the greater-spotted catshark, or nursehound (Scyliorhinus stellaris) are oviparous. This is probably because they live on or close to the bottom of the sea and so can safely hide their egg-cases in the environment in which the pups will grow up. Open water or ‘pelagic’ sharks tend to give birth to live young because they don’t often go anywhere near the bottom of the sea and are too big to hide their eggs in hidden places. Laying an egg in the open water would mean it just sinks to the bottom in the open and likely would be eaten by something on the way down!

Although catsharks are the only group of sharks that lay eggs around the UK, there are several species of rays (other chondrichthyans) which also lay eggs like the blonde ray (Raja brachyura) or the thornback ray (Raja clavata).