Sessile animals are those which are not able to move about. They are usually permanently attached to a solid substrate of some kind, such as a rock, or the hull of a ship in the case of barnacles. Corals lay down their own substrate .
One of a layer of flagellated cells lining the body cavity of a sponge and characterized by a collar of cytoplasm surrounding the flagellum.
In biology, an organism is said to regenerate a lost part, if a substitute for the loss grows from the rest of the organism, and the substitute is a copy or almost a copy of the old lost part.
A hermaphrodite is an animal having both male and female reproductive organs.
The two sexes are not separated into distinct male and female types of individual.
A larva is a juvenile form of animal with indirect development, undergoing metamorphosis.
A phylum of hollow-bodied animals with stinging cells.
Tentacles can refer to the elongated flexible organs that are present in some animals, especially invertebrates.
a polyp is one of two forms of individuals found in many species of cnidar i ans . The two are the polyp or hydroid and the medusa. Polyps are approximately cylindrical, elongated on the axis of the body.
a medusa is a form of cnidarian in which the body is shortened on its principal axis and broadened, sometimes greatly, in contrast with polyps. Medusae vary from bell-shaped to the shape of a thin disk, scarcely convex above and only slightly concave below.