The common name 'cushion star' has been applied to a handful of asteroids that bear a passing resemblance to stuffed upholstery. But the moniker best fits the tropical reef-dwelling oreasterids known as Culcita. Despite their rotund profile, these sea stars possess appendages that are palpable when the animal is overturned. Radiating from the bumpy central disk are five grooves harbouring an ambulacral assembly of tube feet with suckers strong enough to inch the creature over rocky flats.
The limbs, though pudgy compared to those of their knobbly cousins, are more apparent on young individuals. For the ontogenic path of these curious sea stars involves a steady inflation of the internal cavity into a calcified shell complete with structural supports for a carapace with few chinks in its armour. The pin-hard cushions have little to worry from predators, though of late, they risk a greater threat in the plague that has ravaged the region's reefs and turned their preferred prey from cauliflorous polyps into pale, parched stalks. But no rhyme or reason guides these pangs that can die down as soon as they reach a peak, and the shores south of Cyrene Reef still shelter a population of these ineffable cushions that are disarmingly easy to miss as they ply a tenuous landscape of tidal blue and troubled brown.