Characteristics of class asteroidea
What are asteroidea defining characteristics? 1) They have flat, pentagonal or star shaped body. 2) Oral and aboral surfaces are distinct, the oral surface is directed downwards and the aboral surface upwards. 3) They have five to fifty long or short rays or arms radiating symmetrically from central disc. What is unique about asteroidea? The Asteroidea is one of the largest and most familiar classes within the Phylum Echinodermata. The crown-of-thorns starfish, Acanthaster planci, is particularly well-known because it can cause extreme detrimental effects to coral reefs, particularly during population outbreaks (Moran 1988).