Phylum coelentrata

• Asexual reproduction in coelenterates takes place by agmentation and budding
• Coelenterates are hermaphrodites, and sperms are produced by the SAIN
• Fertilisation in coelenterates is internal, and the development is indirect
• Phylum Cnidaria (Coelenterata) consists of radially symmetrical animals
• After fertilisation, the larva develops a larval stage morphologically distinct from the adult
• In Cnidaria, certain ectodermal cells are modified into stinging cells or cnidocytes, which contain a stinging capsule called nematocyst with poisonous fluid
• Cnidoblasts are defensive cells used to kill or paralyse prey and enemies, mainly found on the tentacles
• Coelenterates have a central internal cavity called gastrovascular cavity or coelenteron, opening out by a single opening called mouth on hypostome, with the absence of an anus
• Coelenterates are holozoic and carnivorous in nutrition, with intracellular and extracellular digestion
• Some coelenterates, like corals, have a skeleton composed of calcium carbonate
• Coelenterates have two basic body forms: polyp and medusa
• Polyp is the sessile tubular attached form, with an upwardly directed mouth and tentacles, representing the asexual stage of Hydra