Arenicola cristata

Arenicola cristata, commonly known as a lugworm, is a marine annelid worm found in sandy sea bottoms and intertidal areas. These burrowing polychaetes can grow between 7.5 and 30 cm in length. Their segmented bodies are distinctively colored, with a dark red head, a fatter, lighter middle section featuring bristles and feathery gills, and a thinner, yellowish-red tail.1

Lugworms feed on decaying organic matter, ingesting sand in the process. They create deep burrows, sometimes up to two feet, and their coiled excrement casts are often visible at low tide. These worms are hermaphroditic, meaning each individual possesses both male and female reproductive organs, but fertilization occurs between different individuals. The name Arenicola itself comes from Latin, meaning "sand inhabitant".12