Tough guys or shrinking violets?
Tubeworms, as the name suggests, are worms that protect themselves by living in a hard tube which they secrete around their body. They are a hugely successful group in the world’s oceans today and their fossil ancestors are found throughout the Jurassic and Cretaceous rocks of the Jurassic Coast.
The tube is made of a tough substance called chitin (the same substance that makes up the shells of lobsters and crabs). Others, the Serpulids, use calcium carbonate to make a very hard shell that is cemented to rocks and other animals. Serpulids are the commonest form of tubeworms.
Tubeworms extend their ‘tentacles’ into the water to filter for nutrients and to exchange oxygen. The rest of the tubeworm’s soft body stays safe inside the tube. When threatened by a predator, the tubeworm can rapidly retract the tentacles.
Tubeworms can survive the immense pressures, freezing cold temperatures and total darkness of the deepest oceans. But they are also found in the near-boiling waters around deep ocean hydrothermal vents, the famous ‘black smokers’.
Marine images: Richard Edmonds