THE CORAL FILE
Dead men's fingers, sea fans, Devonshire cups - we've got our own coral reefs! says Paul Naylor
I WANT TO BE ALONE
There are several species of hard coral in our home seas, but all are unusual in living alone or in very small groups. The most common is the solitary Devonshire cup coral which, despite its name, is found around most of the UK. It lives within the little chalk goblet which it constructs.
PLEASE DON'T KICK ME
Sea fans, belonging to the same animal sub-group as soft corals, are another common but exotic sight off British shores. They always grow at right angles to the current, giving each of the colony members maximum access to passing food. Fans take many years to grow, and are doomed if knocked over, so be careful with those fins.
WE DON'T DO AUTUMN
The feeding tentacles which give dead men's fingers their “fuzz” may be retracted for several months in the autumn, while the colonies get ready for spawning. The fingers can become covered in algae and look very unhealthy but, come winter, their surface tissue is shed with any accumulated rubbish.
WE'RE IN THIS TOGETHER
Most corals, soft or hard, are colonial. In colonies, the individual skeletons fuse to form structures such as the lobes of our dead men's fingers or the huge reefs of tropical seas. The animals' feeding tentacles, armed with batteries of stinging cells, protrude from the structures to grasp passing food.
ANEMONES WITH SUPPORT
Corals are the same type of animals as sea anemones, but they produce some sort of skeleton to support and protect their bodies. Stony corals produce a hard, chalky skeleton, while that of soft corals is jelly-like but with embedded chalky fibres to provide strength.
SHAME ABOUT THE NAME
The most prominent coral in UK waters is the soft coral known as dead men's fingers. Hand-shaped colonies can be found in huge numbers on rock faces in current-swept areas. The white form dominates on southern coasts but further north orange varieties are also common. The slimmer and more striking red fingers are a separate but closely related species.