O. nigra is a large brittle star with five narrow arms up to 125mm long and a quite distinct central disc which is up to 25mm … See more

O. nigra occurs in the eastern Atlantic Ocean from Norway south to the Azores, and also the North Sea and the Mediterranean Sea. It is found on rocks, boulders and gravel in the neritic zone down to about one hundred m… See more

O. nigra is a predator, scavenger and filter feeder. It catches pieces of organic detritus and small invertebrate prey with its arms and thrusts them into its mouth. It can scavenge from carcases or graze on algal films. As a … See more

O. nigra is often found living in association with another brittle star, Ophiothrix fragilis. Numerous individuals of these two species sometimes form dense communities with hundreds of brittle stars per square metre. These bed… See more