SHORT DESCRIPTION OF DIVERSIFICATION OR BIO-DIVERSITY:
Due to diversification among the animals, the zoologists have categorized the animal kingdom into the following criterions:
Animals are grouped into two categories on the basis of their shapes and sizes, such as: .
a. Microscopic Animal
Light Microscopic: These animals can be seen well with the help of simplelight microscope.
Example: Amoeba, Hydra Cyclops Daphnia etc.
b. Large Animals: These are not microscopic. These can be seen by nakedeyes. Innumerable small, medium, large and very large animals belong to this group. Example: Ant, Fly, Mosquito. Leech, Earthworm, Cockroach, Frog, Turtle, Lizard Snake, Crocodile, Dog, Cat, Goat, Cow, Bat, Whale, Man etc.
Description of the relative proportion of the shape, structure, SIze etc. of various organs of the animal body is called symmetry. The symmetry of animals is mainly of three types.
a) Asymmetry: Not capable of being halved in any plane, e.g. Amoeba, snailetc.
b) Bilateral Symmetry: Capable of being halved in one and only one plane,e.g. Cockroach, Lizard, Frog, Fish, Man etc.
c) Radial Symmetry: Capable of being halved in many planes, e.g. Hydra,Jelly fish, Star fish, etc.
a) Terrestrial: They live on land, e.g. Cockroach, Toad, Goat, Cow, TigerMan.
b) Aquatic: They live in water.Aquatic animals are of two types:
i. Fresh water animal: Hydra, Singh, Kai, Frog, turtle, crocodile
ii. Marine animal: Lotia fish, Whale, Dolphin, Jellyfish, Shark, Starfish andCoral.
c) Flying: This animals can fly in the sky, e.g. Butterti.y, Bats and variousspecies of birds
d) Tree-living Or Arboreal: They live on trees, e.g. Tree frog, Python, variousspecies of Monkeys, Lemur and Leopard.
e) Desert dweller: They are animals of the desert, e.g. Camel, Dumba etc.
f) Boreal: Rat, Fox, Platypus, some species of snakes, Earth worms etc.
g) Polar: Some animals live in the Polar Regions, e.g. White bear, Antelope andPenguin.
h) Forest dweller: Tiger, Bear, Monkey, Deer, Peacock, various species ofSnakes and Birds, Boar, wild Buffalo etc. They live in deep forest.
i) Mountain dweller: Gayal, Mountain goat, Elephant etc, are animals living inmountain areas.
On the basis of habits animals are of two types; mainly:
a) Diurnal: They are active during day timer e.g. Deer, Squirrel, Cow, Horse,Duck, Hen, Vulture, Butterflies, Hoppers, Eagle and King stock.
b) Nocturnal: These animals are active during night time, e.g. Tiger, Fox, Owl,Moths, Shrew, etc.
a) Herbivorous: These animals eat grass or other plant materials, e.g. Goat,Sheep, Cattle, Elephant, Horse, Rabbit, Guinea pig, etc.
b) Carnivorous: They are generally predacious and feed on animals, e.g. Tiger,Lion, Jackal, Vulture, Hawk, Hyena, etc .
c) Omnivorous: Animals of this category eat all kinds of food, e.g. Cockroach,Crow, domestic Dog, Cat and Man.
a. Holozoic or heterotrophic or zootrophic:
For nutrition they depend upon plants or animals, because they cannot prepare their own food. Heterotrophic animals are again mainly of three types:
i. Scavengers: They get their food from dead plants and animals, e.g.Cockroach, Crow, Vulture, Hyena etc.
ii. Parasites: They take nutrients from other organisms i.e. the host's body.They are smaller in size than the hosts. They live outside or inside the host body e.g. Round worm is an internal parasite of human body and pediculus is an external parasite.
iii. Predators: They are generally bigger in size than their prey animals. Theykill their hunts and eat their flesh e.g. Tiger, Lion, Jackal, Wolf, etc.
Depending on the presence or absence of vertebral column in animal body, animals can be divided into two principal groups. Such as:
Invertebrates: Earthworm, Cockroach, Roundworm, Jelly fish, Starfish,Octopus, Snail, Oyster, Hookworm etc, are the animals without backbones. Vertebrates: Embryonic notochord (an identifying character of the phylum chordata) of these. animals transforms into vertebral column. When fully formed, e.g. Fishes, Amphibians, Reptiles, Birds and Mammals. Vertebrate animals have been placed in the subphylum vertebrata under the phylum chordata ..
Beneficial animals: There are many worms, insects, birds and beasts in theworld which benefit man in various ways directly or indirectly, e.g. Bee, Silk worm, various species of fresh water and marine Fishes, Dog, Cat, Goat, Cow, Horse, Ass, Elephant, various species of birds etc.
Harmful Animals: Many animals do harm to man directly or indirectly, e.g.Mosquito, Fly, White ant, Ribbon worm, Round worm, Snakes. Rat, Tiger, Lion etc.
Though apparently, they are harmful to man, in the animal world all animals in one way or the other are necessary. All animals have a particular role in' keeping the natural balance, food chain etc. So to preserve the existence of animals including the human being, no organisms should be killed unnecessarily. For that the balance of ecosystem may be disturbed, which ultimately will have direct or indirect harmful effects on human society. To understand the beneficial role of animals, every body should have at least a first hand knowledge about the animal kingdom. Animals are valuable and essential resource of a country. It is the duty of all conscious people to be sympathetic towards them and to conserve them. Otherwise many of the animal resources will vanish from the surface of the earth. In the long run the future human society will adversely be affected.