Astrospartus Mediterraneus

Echinoderm

Identification & Biology

• IdentificationA large, extraordinary-looking brittle star with five main arms that branch repeatedly into hundreds of coiling tendrils, forming a basket-like net. Brown to orange-tan in colour. When feeding, the arms unfurl into the current to trap plankton. When resting, it curls into a tight ball.
• SizeArm span up to 70 cm when fully extended. One of the most impressive echinoderms in the Mediterranean.
• Social HabitSolitary. Nocturnal feeder that curls into a compact ball during the day, often wrapped around gorgonian branches or wedged into crevices. Unfurls at night to feed.
• HabitatRocky reefs, gorgonian sea fans, and areas with good current flow. Typically found perched on elevated positions to maximise plankton capture.
• Depth15 to 800 m. Most commonly encountered by divers between 25 and 60 m.
• Feeds OnZooplankton and small organic particles trapped in its branching arm net. A passive suspension feeder.
• DistributionMediterranean Sea and eastern Atlantic. Present in Maltese waters, mainly on deeper rocky reefs.
• DescriptionAstrospartus mediterraneus is one of the most spectacular invertebrates a diver can encounter in Malta. By day it is easily missed, tightly curled into a fist-sized ball on a gorgonian branch. By night it transforms, spreading its hundreds of branching tendrils into the current like a living fishing net. Finding one unfurled is a memorable night-diving experience.