characteristic is the presence of milk producing glands ( mammary glands ) by which the young ones are nourished. They have two pairs of limbs, adapted for walking, running, climbing, burrowing, swimming or flying (Figure . ). The skin of Figure .
Some birds : (a) Neophron (b) Struthio (c) Psittacula (d) Pavo (c) (d) Figure . Some mammals : (a) Ornithorhynchus (b) Macropus (c) Pteropus (d) Balaenoptera (c) (d) mammals is unique in possessing hair . External ears or pinnae are present. Different types of teeth are present in the jaw.
Heart is four- chambered. They are homoiothermous. Respiration is by lungs. Sexes are separate and fertilisation is internal.
They are viviparous with few exceptions and development is direct. Examples: Oviparous- Ornithorhynchus (Platypus); Viviparous - Macropus (Kangaroo), Pteropus (Flying fox), Camelus (Camel), Macaca (Monkey), Rattus (Rat), Canis (Dog), Felis (Cat), Elephas (Elephant), Equus (Horse), Delphinus (Common dolphin), Balaenoptera (Blue whale), Panthera tigris (Tiger), Panthera leo (Lion). The salient distinguishing features of all phyla under animal kingdom is comprehensively given in the Table . .
Level of Organi- sation Cellular Tissue Tissue Organ & Symme- try Various Radial Radial Radial Coelom Pseudo coelo- Coelo- Coelo- Coelo- Coelo- Coelo- Coelo- Segmen- tation Digestive System Incomplete Incomplete Incomplete Circu- latory System Respi- ratory System Distinctive Features Body with pores and canals in walls. Cnidoblasts present. Comb plates for locomotion. Flat body, suckers.
Often worm- shaped, elongated. Body segment- ation like rings. Exoskeleton of cu- ticle, jointed ap- pendages. External skeleton of shell usually present.
Water vascular system, radial symmetry. Worm-like with proboscis, collar and trunk. Notochord, dorsal hollow nerve cord, gill slits with limbs or fins. Phylum Porifera Coelenterata (Cnidaria) Ctenophora Platyhelm- inthes Aschelmin- thes Annelida Arthropoda Mollusca Echino- dermata Hemi- chordata Chordata T ABLE .
Salient Features of Different Phyla in the Animal Kingdom