How many eyes does a spider have?
How many eyes a spider depends on the species. In the natural environment around the world lives 42 thousand species. Somewhat different in appearance, lifestyle, habitat. In the process of evolution, the organs of vision were formed depending on the real needs of the animal. So cave spiders see almost nothing, in horses the power of vision is equal to that of humans.
What are the eyes of spiders
Most members of a huge family are owners of 4 pairs of visual organs. Why a spider 8 eyes, due to their way of life.Practically all the arachnid predators, some hunt, sitting in their burrows, others are waiting in the cobwebs, others are actively looking for prey, exploring the area. Such a number of pairs of eyes in a spider gives him a 360-degree outlook.
Interesting!
The main body that connects the animal with the outside world, are the legs. At the bottom of them are the villi responsible for smell, touch. Arthropod feels the slightest fluctuation of air, gusts of wind, the approach of the victim.
There are rare species of arachnids, which have 12 eyes. There are also owners of only 2 pairs.
Where do spider's eyes
The most important pair of eyes is in front. Externally different from the rest of the size. The rest are on the sides on both sides. The photo of the spider's eye is located below. You can examine them without a magnifying glass in large members of the family - tarantulas, tarantulas, goliaths, etc.
The main organs of vision - the medial, are in front, transmit a general picture. The remaining pairs are side warnings of the approach of the victim, the natural enemy.
On a note!
Some species have faceted eyes. Placed on the sides, externally from the front almost no different.
How does the animal see
The vision of the spiders is blurred. Sees a predator no further than 25 cm from himself. Pictures appear as silhouettes, shadows. Responds well to movement. Scientists also found out that spiders see infrared light emanating from a living creature.
Initially, the picture captures additional eyes, then the focus is concentrated front. A clearer image appears, thanks to which the predator understands that it is an insect, and not an inanimate object.
Interesting!
The eyesight of spiders who weave trapping nets hunt passively, much worse than active relatives. The spider, sitting on the web, picks up the vibrations of the threads, only then brings focus. Horse spiders do not weave cobwebs, do not wait for the prey, they are looking for it. The power of vision is equal to that of a human, the predator notices the victim from afar, but sees everything in black and white.
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