About Spirobranchus kraussii (Baird, 1864)
Spirobranchus kraussii (Baird, 1864), commonly called the blue coral-worm, has a head with two rows of feathery branches. It also has a stalked operculum that features two pointed wings and a flat cap. Adults reach an approximate body length of 15mm, and the inner diameter of their tubes is around 2mm. This species is naturally distributed across the Indo-West Pacific, ranging from the Cape Peninsula to Mozambique, South Africa; it is also found in the Red Sea, Persian Gulf, Australia, Japan, India, Hawaii, and Madagascar. It is an alien species in the Mediterranean Sea, and has also been recorded in the Gulf of Mexico, North Atlantic Ocean, and European waters, with these records linked to past synonym classifications of the species. The blue coral-worm forms massive colonies made of interwoven calcareous tubes. Colonies can be locally abundant on moderately exposed rocky shores, and the species is a filter feeder.
