Final answer:
The aboral ambulacral areas of irregular echinoderm forms are known as petaloids, which are linked to respiration and, in some species, reproduction.
Step-by-step explanation:
The aboral ambulacral areas of irregular echinoderm forms, such as sea stars and sand dollars, are referred to as petaloids. These petaloids are associated with the respiratory system and, in some species, with reproduction. They are a feature that distinguishes irregular echinoderms from the regular forms, which typically have radial symmetry and do not possess the distinct petaloid ambulacra. In star-shaped echinoderms, you would see a central disc with arms radiating from it, but the irregular ones often have a more flattened shape and their ambulacra form flower-like petaloid patterns.