Final answer:
The characteristics commonly found in most echinoderm taxa include tube feet, Aristotle's lantern, blastocoelom, and being monoecious. Echinoderms like sea stars actively use their tube feet for predation.
Step-by-step explanation:
The question asks to select characteristics found in most or all echinoderm taxa and to identify which five out of eight are commonly present. Based on the provided information, the characteristics found in most echinoderm taxa include: tube feet, Aristotle's lantern (in sea urchins), a blastocoelom, and being monoecious, although this can vary among different echinoderm species.
Echinoderms like sea stars and sea urchins are known to use their tube feet for movement and feeding. Sea urchins possess a feeding structure called Aristotle's lantern which helps in grazing on algae or other organic matter. Furthermore, echinoderms have a blastocoelom, which is a type of body cavity, and some species are monoecious, meaning an individual can have both male and female reproductive organs.
An example of an echinoderm that is an active hunter would be a sea star, which can use its tube feet to pry open molluscan shells and secrete digestive enzymes into the prey.