Ynghylch

Sand mason worms are exactly as advertised - they use grains of sand and fragments of shell to build a protective tube to live in. The worm and most of the tube are buried in the sand, with just the top of the tube sticking out. The tops of the tubes can be crowned with an ornate branched structure built of sand and shell. This structure is used for catching food and looks a bit like a mini sand tree. The tops of the tubes can be spotted on beaches at low tide. When the tide comes in, they feed using a pretty crown of tentacles to catch passing particles or search for particles on the surrounding seabed. They can be found alone or in dense beds of thousands of individuals.