Arachnids are ticks, spiders, scorpions
There are hundreds of thousands of different animals in nature. But arachnids terrify many. Although among the large family there are those that do not harm people, but there are also dangerous representatives.
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Who are arachnids
Arachnids are a large family of arthropods. Now there are more than 114000 species. For the most part, they are all predators living on the ground, although there are exceptions.
Arachnids.
Arachnids include:
The structure of arachnids
Different types have very different sizes. The smallest are some mites, they can reach a length of a hundred microns. The leaders in size are some tarantulas and solpugs.
It has two main sections, the cephalothorax and belly. There are no mustaches.
Animals move on 4 pairs of legs. They have chelicerae and pedipalps, which help to catch and capture prey.
The body of arachnids is covered with a thin but dense chitinous cuticle.
In different species, the respiratory organs can be of two types: trachea and lung sacs. A number of small ticks do not have special organs; the exchange occurs through the surface of the body.
All blood vessels have their own walls. The circulatory system is not closed, the main organ is the heart.
There is an organized abdominal nerve chain, anterior and posterior sections of the brain.
Hairs are scattered over the surface of the spider's body, which serve as transmitters that respond to vibrations and transmit information.
Arachnids can have from 2 to 12 eyes. They are located on the cephalothorax and pick up air vibrations on the sides, and not just in front.
In spiders, digestion is partly extraintestinal. They inject poison into the victim, making it semi-liquid, and then drink it.
Depending on the species, arachnids lay eggs, most of them are. But some scorpions and flagellated livebearers.
Distribution and importance of representatives
Arachnids are ubiquitous and perform many different functions.
The value of arachnids in nature and for humans
All living beings have their role. Arachnids are part of the food chain. They themselves feed on small insects, often helping people in the fight against pests.
The members of the family themselves also become food for larger individuals of its kind, arthropods, amphibians and various animals.
Some are the enemies of man:
- spiders bite, causing pain and even more serious consequences;
- ticks parasitize and carry various diseases;
- scorpions they prefer not to touch people and live separately, but if they get into a dwelling or on things, they sting very painfully.
Conclusion
The arachnid family is very large. Among them there are useful and harmful animals. Different species have their own way of life, from predators to parasites. But they all have their own role in nature.
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