Which lineage of Cnidarians exist only as polyps as adults, build calcium carbonate exoskeletons, and have a mutualistic relationship with photosynthetic protists?

Question

Quizplus · Accepted Answer

Anthozoa is the class of Cnidarians that includes organisms such as corals and sea anemones, which exist only as polyps in their adult form. They are known for building calcium carbonate exoskeletons and having a mutualistic relationship with photosynthetic protists, such as zooxanthellae, which live within their tissues.

Which Lineage of Cnidarians Exist Only as Polyps as Adults