External morphology
Most members of the class Asteroidea possess pentaramous symmetry and five arms (Ruppert et al. 2004). The underside of the starfish is referred to the oral surface and the surface of the starfish which is facing out into the environment is known as the aboral surface (Ruppert et al. 2004). The oral surface possesses a distinguishable mouth, ambulacral grooves running down each leg and tube feet (Ruppert et al. 2004). Numerous tube feet are located within the ambulacral grooves (Ruppert et al. 2004). The aboral surface possesses a noticeable maderporite, essentialin the WVS, and an anus, necessary for the removal of wastes (Ruppert et al. 2004).
 
Skeletal structures
The endoskeleton of all echinoderms comprises collagenous connective tissue in addition to calcareous ossicles (Ruppert et al. 2004). This endoskeleton is enclosed by an epidermis (Ruppert et al. 2004). The ossicles are comprised of microscopic three-dimensional lattices called the stereom (Ruppert et al. 2004). The stereom causes these ossicles to take on a honeycomb like structure which aids in reducing the weight of the organism, increasing the strength of the endoskeleton and preventing fractures (Ruppert et al. 2004). These ossicles are also essential in muscle attachment and in ensuring rigidity of the dermal layer (Ruppert et al. 2004). Ossicles of some species may be modified as paxillae or pedicellariae (Ruppert et al. 2004), however N.cumingi does not possess these structures.
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