Red flatworm (rust)

Care at a glance

The rust flatworm is a tiny, flat worm that creeps across corals, rock and sand like a rust-coloured haze. It lives off light via symbiotic algae and multiplies extremely fast: a single worm can bud off new individuals from its rear end.

In itself it does not eat your corals, but in large numbers it covers them completely and deprives them of light. Remove them mainly by siphoning and by bringing nutrients down; chemical treatment can work, but a mass die-off releases toxins, so always filter with activated carbon in that case.

Natural predators

• Six-line wrassePseudocheilinus hexataenia

Related species

• Pom-pom crab (boxer crab)Lybia tessellata
• Berghia nudibranch (aiptasia eater)Berghia stephanieae
• Feather star (crinoid)Crinoidea sp.
• Sally lightfoot crabPercnon gibbesi
• Tiger pistol shrimpAlpheus bellulus
• Dwarf zebra hermit crabCalcinus laevimanus