No, it is immpossible that in a million years that a stony coral are herbivores. The only hebivores in the ocean are phytoplankton, green sea turtles, dugong, and manatees are herbivores of ocean live.
Stony corals are made out of calcium carbonate, usually don't have pores and are in anthrozoan (stationary) colonies, soft corals are porous, "fleshy", and flexible.
An agariciid is any member of the Agariciidae, a family of reef-building stony corals.
It eats sponges and stony corals these two foods are their favorite.
Coral reefs are calcium carbonate. They are built from stony corals, which consist of polyps that cluster in groups.
Hard corals (Scleractinia) - reef-building corals that create calcium carbonate skeletons. Soft corals (Alcyonacea) - lack stony skeletons and have a flexible, fleshy appearance. Brain corals (Family: Mussidae) - named for their distinctive brain-like appearance. Staghorn corals (Genus: Acropora) - characterized by their branching, antler-like growth forms.
Some species use the rocks crevices and overhangs. Some will retreat into a stony structure they build themselves. Some use fish, other crustaceans and sand.
Corals are both producers (they have symbiotic plants living in them) and consumers (herbivores/carnivores) as they filter feed on plankton.
When coral animals die their skeletons remain. More corals build on top of them, gradually forming a coral reef
Corals are classified as members of the phylum Cnidaria, which includes other animals such as jellyfish and sea anemones. Within the phylum Cnidaria, corals belong to the class Anthozoa. They are further divided into two subclasses: Hexacorallia (includes stony corals) and Octocorallia (includes soft corals).
http://www.wonder-okinawa.jp/006/english/hyakka/doubutu/sangorui/index.html Use that link to figure out which type of coral you need! If you just want the general name, though, use Cnidarians
First off, all three types of organims are in the kingdom Animalia, and are not plants, they are animals. Jellyfish and Coral are both in the phylum cnidaria; jellyfish are further divided into class Medusozoa, which has a number of its own subgroups, whereas corals are in the class Anthozoa, which again is subdivided into a number of its own groups, but the what are usually considered corals are mostly in the groups Scleractinia(stony corals) and Octocorallia(soft corals, gorgonians, etc). The sponges on the otherhand are in a completely different phylum, Porifera, which is further divided into many different groups, and is not closely related to the Cnidarians.
The coral reefs are mostly able to grow in clay like material that keeps the coral stable. They just need sand for certain corals and other grow on solid rock surfaces. It just depends if the coral is a Small polyp stoney corals or a large polyp stony or some other kind of soft coral.