Opheliidae is a family of small, annelid worms.

Some of the genera, like Armandia, Ophelina and Polyophthalmus, have lost their circular muscles.

[2] The Opheliidae family of polychaete; marine annelid worms[3], play an essential role in marine ecosystems as “deposit feeders” that aid in the recycling of nutrients and sediment mixing in muddle and sandy habitats.

[4] Due to their distinctive adaptations that include streamlined bodies and specialized muscles they can burrow in various marine environments.

[5] Worms in the Opheliidae family generally show characteristics of having a smooth body, a ventral (front) crease, few flaps on their sides and a pointed head to help them travel through mud and sand.