Planaria (flatworm)

Care at a glance

Planaria are flatworms that glide across glass and substrate, recognisable by their triangular head with two cross-eyed eyespots. They are famous for their regeneration: cut one in half and two complete worms grow from it, so chopping them up is counterproductive.

They mainly eat leftover food and dead material, but in a shrimp tank they are a real problem because they attack eggs and newborn shrimp. They almost always appear with over-generous feeding; reduce the ration, siphon them out or catch them in a trap, and use only treatments explicitly labelled as shrimp-safe.

Good to know

• Active at night
• Preys on shrimp and snails

Natural predators

• Yoyo loachBotia almorhae

Related species

• Spixi snail (zebra apple snail)Asolene spixi
• Redclaw crayfishCherax quadricarinatus
• Red claw crabPerisesarma bidens
• Vampire crabGeosesarma sp.
• Giant freshwater shrimpMacrobrachium rosenbergii
• Japanese trapdoor snailViviparus malleatus