Brown Brittle Star

Echinoderm

Identification & Biology

• IdentificationA large brittle star with a small central disc and five long, smooth, flexible arms. Dark brown to chocolate on top, paler underneath. The arms are banded with lighter and darker brown. The disc surface is covered in fine, smooth plates.
• SizeDisc diameter up to 3.5 cm. Arm span up to 30 cm.
• Social HabitMostly nocturnal. Hides under rocks and in crevices during the day, with only the arm tips visible. Emerges at night to forage across the reef.
• HabitatRocky reefs, under boulders, and in crevices. Prefers sheltered positions with easy access to open substrate for night feeding.
• Depth0 to 50 m. Common in the shallows to about 20 m.
• Feeds OnDetritus, small invertebrates, and organic particles. A scavenger and deposit feeder that sweeps the substrate with its flexible arms.
• DistributionEastern Atlantic and throughout the Mediterranean Sea. Common in Maltese waters.
• DescriptionOphioderma longicauda is the largest brittle star commonly encountered in Malta. During the day, look under rocks and in crevices where several may shelter together with just their arm tips showing. At night, they emerge onto open reef and are one of the more active echinoderms visible during night dives. The arms move in a serpentine motion, quite different from the rigid movement of starfish.