Today is #WormWednesday on Twitter, and we figured that it was a good day to introduce you to this rather unlucky fellow and his sidekick…

The orange part (coloured in Photoshop) is the parasite. The two long sacks are filled with eggs.

They were collected during our field work in Sletvik in October. The worm is a polychaete in the genus Terebellides, whilst the parasite is a Copepod. This species rich group of small crustaceans have many modes of life, but parasitism is a common one, with about half of the ~13 000 species being parasites.