RESPIRATORY ORGANS IN ANIMALS -

1. In Protozoa plasmalemma functions as respiratory surface.
2. In Porifera, respiration occur through body wall.
3. In Coelentrata respiration occur by body wall.
4. In platyhelminthes mostly anaerobic respiration occur. Otherwise by body wall.
5. In Ascahelminthes in pseudocoelomic fluid cytochrome, Hb present.
6. In Annelida by body wall (Earthworm), gills (Sabella), Perapodia (Nereis).
7. In Arthropoda by gills (Crustacean), Trachea (Insects) and book lungs (Scorpion, Spider).
8. In Mollusca by Ctenidia, Pulmonary sac.
9. In Echinodermata by Bursae, Dermal Papullae.
10. In Pisces by gills. Accessory respiratory organs as air bladder, swim bladder may present.
11. In Dipnoi (lung fishes) by lungs.
12. In Amphibians by skin, buccal cavity and hollow lungs. In Amphian's tadpole by gills.
13. In Reptiles by lungs. Left lung is rudimentory in snakes.
14. In Aves by spongy lungs. Air sacs also present. In Mammals by solid lungs.