Starfish

Starfish belong to the phylum Echinodermata (q.v.,) and the class Asteroidea. A short account of the anatomy of the commonest English Starfish is given under Asterias, and of the classification under Asteroidea. There are forty-two species living in the British seas; they mostly inhabit shallow water, but many are found in very deep water: thus Nymphaster ranges down to 9,000 feet. The best-known British species are the Sun Star (Solaster papposa), which has many rays from a central disc; the thin leathery Palmipes; the tiny pentagonal Asterina gibbosa; the long-armed Luidia, famed for the suicidal habit of voluntarily breaking up its body; Asterias rubens, the common English Sand Star, and its larger and more northern ally, Asterias glacialis.