Classification of Backboners
Generally, animals in the world are divided into two big groups; invertebrate and vertebrate. Invertebrate is an animal which has no backbone. In contrast, vertebrate is an animal which has backbone. Vertebrate animal is more complex than invertebrate animal because vertebrate animal has already had blood circulatory system, cardia or heart, and respiratory system. They are five classification of vertebrate animal; pisces, aves, amphibian, reptile, and mammal. Even though there are five classification of vertebrate animal, I will discuss only 3 of them; pisces, aves, and mammal.
The first classification of vertebrate animal is pisces. Pisces is a kind of animal which mostly live in water. As you know pisces has distinct appearance than aves and mammal. Pisces has scale and fin, and those two things help pisces to live in water. Besides, pisces is also completed with gill and heart with two chambers; a ventricle and an atrium. The example of Pisces is all kind of fish except shark, dolphin, and whale. Shark, dolphin, and whale are not pisces, although they live in water. They are mammal because they have mammal characteristic; deliver their baby and have mammary gland.
The next classification is aves. I may say that aves mostly live in branches of tree, but not all aves. Goose, chicken, and duck are the example of aves which live on the land. Aves is created with special design to make them able to fly. Aves has no fin, but it has wings to fly. Its body is also not covered by scale, as pisces is, but it is covered by feathers which enable it to fly. These special designs make aves’ appearance is different from pisces. Not only the appearance design, but aves also has special shape of mouth which is called beak; this beak helps it to survive in its habitat. In addition, aves is also completed with pneumatikus, heart with four chambers, and complex blood circulatory system. The examples of aves are all kind of birds, chicken, duck, and goose.
The last classification is mammal. Mammal is the most complex animal of all. It has already had complex system. In appearance, mammal is different with pisces and aves. Mammal does not have scale or feather, but it has fur which covered all of its body. It also does not have fin or wings. However, mammal has hand to replace the fin and the wings. It is easy to differentiate mammal with other animals, because mammal has special physical characteristic which can not be found in other animals; glandule mamae or mammary gland and pinna or ear lobe. Mammal is also designed in complex system and shape. It is completed with lung, heart with four chambers, and complex blood circulatory system which makes mammal has complex body system. The examples of mammal are human being, elephant, whale, shark, rabbit, and etcetera.
Based on the explanation above, eventhough mammal, aves, and pisces are vertebrate animal, they do not have the same physical characteristic. Pisces is just like a simple form of vertebrate. It is shown from their blood circulatory system. If Aves and Mammal have already had complex blood circulatory system and heart with four chambers, Pisces only has simple blood circulatory system and heart with two chambers.
No comments:
Post a Comment