The Red Comb Star is often incorrectly spelled as A. aurantiacus or A. aurantciacus, too. With an arm span of up to 60 cm it is he largest species of the family.
Its colour can vary from red-orange to light-brown, the ventral side with the tube feet is yellowish. The periphery of the five arms bears one row of large, 1-2 cm long, white prickles and several rows of small spines. The next inner row of skeletal plates carries two rows of small spines. The upper surface is arched and shows numerous red-orange to brown paxillae instead of pedicellariae for protection. The tube feet, on the ventral side of the arms, are conical without suckers but with an adhesive coat at the tip.
The Red Comb Star is nocturnal or crepuscular and feeds voraciously on molluscs. Spines around the mouth help to hold the prey. There is no anus which means that any undigested food has to be expelled through the mouth.
During the day the animal is buried in the sand and the disc is swollen in order to react if touched by digging deeper.