Macrostomum

Macrostomum
Temporal range: No fossils known
Macrostomum lignano
Scientific classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Platyhelminthes
Family: Macrostomidae
Genus: Macrostomum
Schmidt, 1848

Macrostomum is a genus of flatworm with a worldwide distribution, with over a hundred species described to date. These hermaphroditic, free-living flatworms are usually small in size, with large species reaching up to 5 mm in body length (e.g. Macrostomum tuba). They are usually transparent, and the smaller species appear rather round in cross-section than dorsoventrally flattened.