Lomanotus marmoratus is a species of a sea slug, a marine gastropod mollusc in the family Lomanotidae.

This species was described from Berry Head, Torbay on the south coast of England.

[1] It has been reported from Atlantic coasts from Great Britain to Spain to Great Britain and also from the Mediterranean Sea.

Lomanotus marmoratus feeds on the hydroid Nemertesia antennina[2] family Plumulariidae.

This Heterobranchia-related article is a stub.