A small brittle star with very long arms which lives buried in muddy sand. Disc may be up to 11 mm in diameter with upper and underside surfaces covered in small smooth scales. Each arm segment has between 4-6 short spines on each side, none flattened or widened at the tip and two large tentacle scales. Colour in life reddish or greyish-brown, often somewhat mottled.Other Amphiura species are similar. Mixed populations of Amphiura chiajei and Amphiura filiformis are common.