Sand Fan Worm

Overview

The Sand Fan Worm is a sedentary polychaete that lives permanently within a thick, transparent, and gelatinous tube. These worms are typically found buried in soft sediments, with only their distinctive feeding crown extending into the water column.

Appearance

This species features a stout, cylindrical body that can reach lengths of up to 20 cm. A defining characteristic is its feeding crown, which consists of tentacles joined by a membrane to form a funnel shape. These tentacles are often purple or brown, with the tips remaining free. Unlike some other fan worms, it lacks a thoracic collar, instead possessing a triangular flap on the first segment that covers the oral area.

Distribution & habitat

These worms are widely distributed across the North Atlantic, the Mediterranean Sea, and parts of the English Channel and North Sea. They inhabit soft substrates, including mud, muddy sand, and muddy gravel, ranging from the intertidal zone to deeper, shallow waters.

Biology & behavior

When threatened or disturbed, the worm rapidly retracts into its protective mucus tube, a movement that can reduce its visible length by half. The tube itself is often covered with a light layer of fine sand grains. The worm's mucus has been noted for its potential antimicrobial properties, which may provide the animal with chemical protection.