PHYLUM

COELENTRATA

---- ARYAMAN SINHA IX A

GENERAL INFORMATION• Coelenterata is scientifically classified from the

Animalia kingdom and Eumetazoa sub-kingdom. The term Coelenterata is no longer recognized as scientifically valid, as the Cnidaria and Ctenophora. 

• This phylum includes about 9000 species , which are mainly marine ; few are fresh water . The name of this phylum came from the stinging cells or cnidoblasts present on the ectoderm of tentacles and the body of these carnivorous animals. This phylum includes aquatic (marine and fresh water), solitary or colonial forms.

Characteristics

• Dipoblastic body with two layers of cells, outer layer called ectoderm or epidermis and the inner layer known as the endoderm or gastrodermis.

• The body is made up of two layers of the cells , one makes up cells on the outside of the body , and the other makes the species live in colonies like corals , while others have a solitary life-span like hydra . Jellyfish and sea anemone are common examples

• There skeletons are generally composed of minerals like calcium carbonate.

• Medusae(a organism like jelly fish) generally have only hydrostatic skeletons.

• Coelenterates are generally carnivorous in nature, except some species, such as coral .

Special features• They have a tissue level of organization and lack organs

and organ systems.• Most of these animals have radial symmetry.• Many Coelenterata form a hard skeleton made of lime.

These are corals like hydra.• Coelenterata exhibit two body forms . The polyp and

medusa , polyp lead solitary or colonial life but are always fixed , while medusa are free swimming like jellyfish.

• It consists of the three class namely--- (1) Hydrozoa (2) Scyphozoa (3) Anthozoa

Three class of Coelenterata

• Hydrozoa - includes the freshwater Hydra, the marine Obelia, the Portuguese man-of-war (Physalia), and Gonionemus.

• Scyphozoa - the common jellyfish as Aurelia.

• Anthozoa - the sea anemones, sea pens, and corals.

ExamplesAcropora palmata (Elkhorn coral) Aurelia aurita (Jelly fish)

Distichopora violacea Hydra

Sea AnemonesThere are more examples for Coelenterata like Obelia , Millepora(coral), Physalia , Porpita. They have tentacles and are aquatic animals as you can see in all the example photos .