Animal profile

Lugworm

Arenicola marina

PolychaetaU-shaped burrows in intertidal sand and muddy sand flats

Field profile

Arenicola marina is a stout burrowing polychaete found on European beaches, recognised by the coiled sand casts it leaves at low tide. It swallows sediment, digests the organic content and ejects the rest. It is dug commercially for angling bait.

Published field notes

2025-05-27

Lugworm

Every lugworm cast has a matching depression nearby

The coiled sand cast on a beach is one end of a U-shaped burrow. A few centimetres away sits a shallow funnel marking the head shaft, where the worm draws sediment down and feeds beneath the surface.

Read with evidence →