Spirobranchus kraussii

The Blue coral-worm (Spirobranchus kraussii) is a species of marine invertebrate in the family Serpulidae of order Sabellida. It is native to the Indian Ocean.
Description.
The head has two rows of feathery branches and a stalked operculum with two pointed wings and a flat cap. Length about 15mm and tubes are about 2mm inside diameter.
Habitat.
The Blue coral-worm builds massive colonies of interwoven calcareous tubes, which can be locally abundant on moderately exposed rocky shores. It is a filter feeder.