Six-armed brittle stars in orange and yellow, wrapped by the dozen around gorgonian branches.
Very small brittle stars with a disc of about 5 mm and arms two to three times that, coloured bright orange, yellow, red or white, often with banding on the arms. The character that separates them from every other brittle star on the same ground is the number of arms: six rather than five. They are found wrapped around the branches of gorgonians and whip corals and on the surfaces of sponges, with the arms curled tightly to the host.
Six arms and the small size are a consequence of how they reproduce. The animals divide across the disc, each half regenerating the missing part, so a host colony carries a population of clones and the individuals on one sea fan are frequently all the same colour. Counts on a single fan can run to dozens, and a heavily occupied colony looks as though it has been dusted.
They are suspension feeders, taking particles from the water with the tube feet and the arm spines, and they gain height in the current from the host. Whether the association costs the gorgonian anything is not settled. Recorded from about 5 to 35 m.
Ratings are per location: 1 means found on most dives that look for it, 5 means a handful of records. Where enough dives have been logged the figure is calculated from them; otherwise it is an editorial estimate, and says so. We publish habitat and destination, not the dive site.
