The Bootlace Sea Worm is believed to be the longest worm in the world and can be found all around the shores of England, although it is very rarely seen. It is called a Ribbon Worm because it has a very long thin flattened body that is not divided into segments like many other worms. It also has a ‘proboscis’ which is a long, thread-like tubular sucking organ that shoots out of the worm’s mouth when it wants to feed.

The Bootlace Sea Worm can reach up to thirty metres in length, but is usually around five to fifteen metres long and about five millimetres wide. It lies curled up under large stones and muddy sands in shallow waters and rock pools. It is dark brown or black with a purplish sheen. Its head is only slightly wider than the rest of its body and it has around ten to twenty dark coloured eyes on each side of its head.

The eggs are laid in a string-like gelatine mass in the sea where they are left to develop and hatch. The larvae first become part of zooplankton before they settle on the seabed to develop into adult Bootlace Sea Worms.