Sand Mason Worm (Lanice conchilega)
The Sand Mason Worm fashions a tube made from cemented sand grains and tiny fragments of seashell. It has a frayed edge around the mouth, and can be seen at low tide protruding from the sandy beach.
The worm itself is pink, yellowish or greenish with white tentacles and red gills. It can have up to 300 segments, and grows up to 30cm long.
It may be found solitary or in great masses, and as many as several thousand can be within one square metre. Found on exposed and sheltered beaches where it feeds on organic food particles beneath the water via its tentacles which protrude from the top of its protective tube. Common and widespread.
Photograph taken August 2011, Saundersfoot, Wales.