© Johan Boshoff

Common family name


Scientific name



Flatworms measure 10 cm on average but can be as long as 30 cm.


Flatworms have flattened, smooth bodies which are somewhat shaped like a leaf, and a frilly margin at its mantle edge. It has two tiny rhinophores near the edge of its head. Some have finger-like protrusions on their body surface. Flatworms vary in colour from a blotchy brown, green and grey to black and vivid orange.

General Info

Flatworms belong to the Pseudocerotidae family which includes parasitic tapeworms and flukes. They use their smooth bodies for oxygen exchange. With their fine hairs and muscle contractions, they can move fast on the seabed. They use their proboscis to catch their prey and have no anus as their gut ends blindly. Flatworms are hermaphrodites which cross-fertilise and lay a string of eggs.


Flatworms feed on tiny crustaceans, molluscs and worms.


They can be found in all temperate and tropical oceans around the world.

Common Species

Candy-striped flatworm - Prostheceraeus vittatus
Yellowspot flatworm - Thysanozoon nigropapillosum
Splendid flatworm - Pseudobiceros splendidus

© Johan Boshoff