Protula bispiralis, commonly known as the red fanworm or as a mopworm, is a species of marine polychaete worm in the family Serpulidae.

[1] Red fanworms have bodies which grow to 65mm in a tube of up to 10mm in diameter.

They are lovely fanworms, having a white shell-like tube and two bright orange-red spirals of feathery branches protruding from it.

[2] These animals are found off the southern African coast from Cape Point to Durban, subtidally and to at least 25m.

[2] These animals grow under boulders or crevices, and are often seen on vertical rock faces.