….is a species of marine Spoon Worm (Phylum Echirua) which is commonly known as the “fat innkeeper worm” or “penis fish”. Urechis unicinctus is distributed along the along the coasts of Japan and surrounding areas. Urechis unicinctus like other members of the genus Urechis spends most of its life hidden in a self made U-shaped burrow. It is a suspension feeder and will feed by pulsating its body to drive water though its burrow, it will then produce a mucus net that lines the burrow and any edible particles caught on the net and the net itself are then eaten.
Image: J. Patrick Fischer