how many teeth does a crocodile have ?

animal species

• Animals are divided into the following types :

1. invertebrates
2. fish
3. Amphibians
4. reptiles
5. the birds
6. Mammals

• invertebrates :

They are animals that lack a backbone or a backbone, and invertebrates constitute the largest animal group on Earth, they make up 97% of all animal species, and their sizes range from microscopic mites and flies that can barely be seen to the giant squid whose eyes are only the size of its eyes.  Football, and until this moment more than 1.25 million species of invertebrates have been discovered, most of them are insects, and it is believed that many other types have not yet been discovered, as the number of invertebrates can reach 5, 10, or even 30 million species, and invertebrates are quickly characterized, For example, sponges and corals reproduce with eggs and sperm, while some types of insects such as ants and bees reproduce with eggs that develop without fertilization to produce working insects.

• fish :

It is one of the five basic categories of vertebrate animals, while the other four are mammals, reptiles, amphibians, and birds. Fish have fins that help them swim and gills that enable them to breathe oxygen underwater.

 Other groups are merged. Fish vary greatly in shape, color, and size according to different species, they may be in the form of worms with twisted bodies, or flat so that they are almost flat, or look like a rock, and the smallest size does not exceed one and a half centimeters in length and the largest is the whale shark, which is more than twelve meters long. 

This fish lives in all water bodies on Earth, in very cold arctic waters, and lives in tropical waters that almost reach the boiling point, and in rivers and mountain streams that run under the surface of the earth, and some species live most of their lives buried in the mud or sands of the seabed And fish are of great importance to humans. Many pet lovers serve as pet fish, and some of them may be harmful to humans. Sharks, piranhas, and barracudas in some cases attack humans, with bites of some poisonous substances. Fish cause death.

•  Amphibian :

Amphibians or amphibians are one of the five basic groups of vertebrates, and they are distinguished from the rest of the animals in that they can live in the aquatic environment and on land, and their skin is devoid of scales and may reproduce in water or on the wetland.  , and the Sicilian (legless amphibians), and its combined population is approximately 7,400 different species living in different regions of the world.  

Amphibian species in the world are currently threatened with extinction

• reptiles : 

The group of reptiles is one of the descended organisms of the category, which has been classified since antiquity based on its external shape and appearance, and all amniotes descend from it, except for birds and mammals.  Their body).

 Reptiles are a group of vertebrate animals that breathe in the air, and usually live in tropical and temperate regions, and two types of them live in European and polar regions, and the sizes of reptiles vary significantly according to their types;  Some of them are very small, such as the dwarf gecko, and some of them are large, such as giant turtles

• the Birds :

Birds: Birds are known as two-legged vertebrates whose bodies and wings are covered with feathers, and they have a bony beak in front of the face without teeth, and most types of birds can fly and fly in the air at different heights and for long distances, while some types of birds cannot fly,  Many of them can also run, jump, swim, dive and walk.

  Birds are found in various types of habitats on the surface of the earth, and the ostrich is the largest bird, with a length of about (2.7) m, while the smallest is the hummingbird, whose length is (5  ) cm, and birds have a digestive system that gives them the ability to pick up food using their beak and eat it in flight, and then digest it at a later time, and birds are known to lay their eggs in the nest and incubate it for a certain period

• Mammals : 

They are a vital branch that includes living organisms whose body is covered with hair, and they breastfeed their young through the mammary glands.

 There are approximately 4,600 species of mammals on the surface of the globe, all of which are similar in several characteristics that combine them.