What primary characteristics of animals are not exhibited by the porferans?

Poriferans, or sponges, lack several primary characteristics of animals, including true tissues and organs, which distinguishes them from more complex animal forms. They also do not possess a nervous system or muscles, leading to a lack of coordinated movement. Additionally, poriferans are primarily sessile, meaning they remain fixed in one place, unlike most animals that exhibit mobility. Their body structure is simple, consisting of a porous body with specialized cells for filtering water rather than organized systems found in other animal groups.