Of all the classes of animals - higher and primitive - many species use different from each other means of movement (sometimes very original) on water, under water, in the air and on surfaces. The methods of movement of animals depend on many factors: the formation in the process of evolutionary development, the presence or absence of a skeleton, and other structural features of a particular species.
The most important feature
The ability to move is one of the properties of living organisms, no matter what class or species they are considered by scientists. Even plants move internally at the cellular level. And animals, unlike plants, tend to move the whole body, thereby pursuing various goals: the search for food, reproduction, protection from enemies. Because the movement - this is the very life of wildlife and, in particular, its fauna.
Ways of moving animals. Classification
All of them are divided by type into several large groups.
- Amoeboid. The name comes from the word amoeba. This simplest animal does not even have a constant shape, and its body consists of one cell and has the ability to constantly change shape. On the body, peculiar outgrowths are formed, called pseudopods (pseudopodia). Thanks to these devices, this simplest one is able to move around. Under the microscope, which is strong enough, you can see how it, as it were, rises on short outgrowths, like on the paws, and rolls, performing a motor process.
- Reactive. Some other simplest ones (for example, gregarins) move in this way, sharply isolating mucus from the end of the body, which pushes this animal forward.
- There are also protozoa that hover passively in any medium (for example, in water). And what are the ways of moving unicellular animals? They differ in an enviable variety.
- With the help of flagella and cilia. Such animal movements are also characteristic of protozoa. Devices carry out various movements: wave-like, oscillatory, rotational. With the help of these movements the animal itself (for example, euglena) moves, making a spiral trajectory. According to Norwegian scientists, some flagellates living in the seas can rotate around their axis at great speed: 10 revolutions per second!
- With the help of muscles. These methods of movement of animals are characteristic of many species with a muscle structure or its similarity. With the help of muscles, all mammals, to which humans belong, also move.
Evolutionary development
During the evolution of animals from the simplest and unicellular structures of organisms to higher multicellular organisms with various organs and functions, animal movement methods have also evolved. Over millions of years, complex motor systems have been developed that allow different species to obtain food, run away from the enemy, defend themselves and multiply. It is characteristic that only a few of the known animals carry out a sedentary lifestyle. The vast majority travel in various ways.
Using muscles
For multicellular representatives of the fauna, the movement is accomplished using muscles that are formed by a special tissue called muscle tissue. This structure has the feature of shrinking. While contracting, the muscles set in motion the levers, which are the components of animal skeletons. So the movement is carried out.
Who is what
So, with the help of muscle structures, slugs and snails glide on surfaces. Earthworms, using abdominal muscle movement, cling to the uneven soil with their bristles. Leeches use suckers, and snakes use skin flakes. Many animals, lifting the body above the ground, move with the help of limbs, thereby significantly reducing friction. As a result, the speed of movement also increases (the fastest animal on the planet is the cheetah, which has a speed of over 110 kilometers). Some animals jump (even on water). Some plan in the air or fly. Some dive or swim in the water or in the depths. But muscle is used everywhere.
Unusual ways to move animals
- Freshwater hydra moves with the help of peculiar steps and somersaults. She bends the body and attaches tentacles to the surface, then pulls up the sole. And sea anemones move very slowly, contracting and relaxing the muscles of the sole itself.
- Cephalopods (squid, octopus) are capable of reactive movement. They suck in liquid in a special cavity of their body and forcefully eject it through a narrow funnel. Thus, the body is moved in the opposite direction.
- Basilisk lizard quickly runs through the water (2 meters per second). On the surface of the water it is held by air bubbles under the scales of the paws.
- A gecko runs along a vertical glass wall at a speed of 1 meter per second without falling. This is due to special suction cups on the legs of the lizard.
- Paradise decorated snakes that live in Asia fly through the air from tree to tree, using the flattening of their body, which turns into a flying saucer for this time .
Summary
Various types of movements are characteristic of all animals existing on our planet. The process itself is carried out in several ways. Each of the living organisms is adapted to certain types of movements characteristic of it.
This material can be used to conduct a lesson on the topic “Methods of movement of animals. Grade 5 ".