CHARACTERS OF VERTEBRATES:
Vertebrates show the following characters, besides the chordate characters.
, 1. PRESENCE OF ENDO AND EXO-SKELETON: Vertebrates include internal skeleton which is a notochord or vertebral column. Vertebrates contain exoskeleton, made by scales or dermal plates etc.
2. CEPHALLZATLON - The vertebrates develop a head with brain and sense-organs. The development of the head is called cephelizalion .
3. PRESENCE OF CRANIUM : In all vertebrates cranium is present. The cranium surrounds the brain.
4. PRESENCE OF POST-ANAL TAIL : In all vertebrate animals a post- anal tail is present in the adult or in the embryonic stages.
5. PRESENCE OF PAIRED APPENDAGE : Vertebrates possess two paired appendages. They may be fins or limbs. In fishes fins are present. ln tetra pods two pairs of limbs are present.
6. PRESENCE OF VENTRAL HEART: In all chordates especially vertebrates a muscular heart is ventrally situated.
7. PRESENCE OF CLOSED BLOOD VASCULAR SYSTEM: In chordates the blood flows in the closed vessels of blood vascular system.
8. PRESENCE OF HEPATIC PORTAL SYSTEM: The hepatic portal system is well developed which connects the digestive system with the liver:
The importance of the hepatic portal system is that the excess of carbohydrates are removed and glycogen is stored in liver.
9. PRESENCE OF RED BLOOD CORPUSCLES: Hemoglobin is con- fined to R. B.C. They are helpful to carry respiratory gases.
10. PRESENCE OF PITUITARY BODY : In the vertebrates a pituitary body is present beneath the fore-brain. The pituitary body produces several hormones, which are essential for the normal growth and functioning of the body of vertebrates. . .
1 1. DEVELOPMENT OF ENDOCRINE SYSTEM : Endocrine glands do not possess ducts. Their secretions are directly liberated into the blood. These secretions are called hormones. The function of the hormone is to bring coordination among the functions of all the organ systems of the body.
Thus all the Chordate animals possess these basic chordate characters commonly.