Mysteries of the deep

Wild and wonderful life in Britain’s seas

THE WORLD’S LONGEST-LIVING ANIMAL

Found in sandy seabeds, the ocean quahog’s age can be found by counting rings on its shell. The oldest was dated at 507 years old.

THE PREGNANT FATHER

Britain is home to two species of seahorse: short-snouted and spiny. It’s the male that goes through ‘pregnancy’ keeping the eggs in a brood pouch until live young emerge.

THE ECHINODERN THAT REGROWS LIMBS

Found in rockpools around the UK, common starfish can regenerate lost limbs, so look out for one with a shorter leg that is regrowing.

THE JELLYFISH AS BIG AS A DUSTBIN LID

The barrel jellyfish is the largest found in UK waters. They can grow up to 3ft across and are often found washed up on beaches.

THE MANY-EYED MOLLUSC

Great scallops have around 200 eyes that allow them to detect predators and then escape by opening and shutting their shells to send out propulsive jets of water.

THE FISH THAT CHANGES SEX

One of the UK’s most colourful fish, the cuckoo wrasse starts life as a female but the alpha can change sex when the dominant male on a reef dies.

THE SLUG WITH CHEMICAL WEAPONS

The orange-clubbed sea slug can be found on the lower shore. Its colourful ‘clubs’ can taste, smell, and put out foul chemicals to stop predators.

THE ANGELIC SHARK

Over 40 species of shark live in UK waters and one of the world’s rarest, the angelshark has a small population in west Wales, although it’s at risk from seafloor trawling.