Serpula

Genus of marine bristle-worm (polychaete), whose members secrete a trumpet-shaped calcareous tube. The tube, which is fixed to rocks or shells, serves as a protective retreat from which the worm extrudes whorls of tentacles (radioles) to trap suspended particles. The remains of colonies of serpulids often form reddish-coloured rocks, or assist in the formation of a substratum for coral reefs.

Classification Serpulais in class Polychaeta in phylum Annelida.