Saturday, October 22, 2016

Phylum-Coelenterata (Cnidaria)

  • The animals are aquatic, mostly marine.
  • These may be of two type i.e. medusa (free living) and polyps (sessile).
  • Animals are radially symmetrical.
  • Animals are diploblastic (body wall consists two layers outer epidermis and inner gastrodermis separated by mesoglea.
  • Body cavity is called gastrocoel and forms gut without anus.
  • Stinging cells i.e. nematocysts are found in body.
  • Reproduction is asexual (budding) and sexual.
  • Fertilization is external.


Ex-Hydra ,Jellyfish,Sea-anemone etc.
Hydra 
Hydra

Jelly-fish

No comments: