Features of the sight of arachnids: how many eyes do scorpions have

Unlike developed species of arthropods, the sight of arachnids is weak. Their eyes have a simple structure. On the body, there may be up to six pairs, but this confirms the fact that they are not perceiving the world around them. The answer to the question of how many eyes the scorpion can not give a clear understanding of the quality of its visual system. Therefore, it makes sense to understand how he has adapted to survive with such an imperfect "optics".

Features of the sight of arachnids

Different species groups of this class have adapted well. For many, the primary role is played not by the eyes, but by tactile sensations. On the surface of the body they have areas with increased sensitivity. Especially a lot of tactile hairs on the articulated paws responsible for movement, and on pedipalps (tentative).

Many arachnids wove fishing nets. By the smallest vibrations of the threads, they will learn about the caught prey. In this case, visual perception is less important. Kinds leading a nomadic way of life and hunting without a web, have a more developed vision. To travel in an unfamiliar terrain, they must be able to distinguish the surrounding reality.

However, their visual system does not go in comparison with the "optics" of developed higher insects. The eyes of the scorpion (photo below) also do not differ either by the complexity of the device, or by the peculiarities of the color rendition. It is believed that the representatives of this suborder are even worse than spiders and are able to distinguish themselves similar only from a distance of several centimeters.

Simple and complex vision of arthropods

Vision in insects is most developed. In this regard, the eyes of arachnids are often called simple. In developed representatives of insects - bees, dragonflies, flies and the like - complex eyes have a facet structure. The structural visual unit is ommatidia. Of these, in fact, is a complex optical system. Located next to each other, they form a visual complex. Ommatidia consists of a biconvex lens (cornea), under which there is a transparent cone, similar in properties to the lens.

Below is a layer of cells (the retina), capable of perceiving light radiation. They connect to the nerve endings that transmit signals to the brain. From each ommatidy information comes separately. As a result, the picture consists of many points and resembles a mosaic image.

In flies, the number of such structural elements reaches 4 thousand in each eye. More developed dragonflies in this plan and more - up to 28 thousand. It is known that arachnids have several pairs of eyes. How many eyes do scorpions have a complex structure? They do not have a complex visual system. It is represented by several separately located osmatidia eyes. And one of their larger pairs is considered the main one. The remaining (up to 5 pairs) are located on the side and are considered auxiliary.

Simpler lateral eyes (stems) are found in insect larvae. Going to the higher stage of development, their visual system becomes more complicated. Another type of simplified eyes (dorsal) does not "degenerate", but remains at the same level in adult individuals. Ommatidia is not formed in them (there is no cone and lens). Under the cornea are light-receiving cells. Even lower is the pigment layer, connected to the nerve endings.

Scorpions: a way of life

These arthropods are most often found in regions with tropical climates. Some species lead a daily life, but the overwhelming majority of them are still night hunters. They prefer to hide from the scorching heat and hide during this period under rocks, snags and other secluded places.

This is partly due to their imperfect vision. They can only notice danger from a close distance, and hunting is better adapted at night. But this is not only because of the specific features of vision. It does not matter how many eyes the scorpion (photo below) - they do not play a decisive role in catching prey. It is believed that the main merit of accurate attacks is the sensitive sensors on their paws.

The circular setting of the feet gives the scorpion an opportunity to feel the smallest fluctuations of the soil from all sides. By the speed of propagation of such signals (nearer paws feel them earlier), it determines the exact location of the victim. The eyes in this play a secondary role. It is noted that if you divide the scorpion and the victim by a barrier in the form of a thin cleft, it will not be able to attack it even from a close distance. Signals on the soil from the transfer of production to its sensitive legs in this case do not reach.

How many eyes do scorpions have

The habitat and the features of life significantly changed the appearance of these creatures. Distinguish not only the overall size of the body and its individual parts, but also the number of eyes. Regardless of their total number, they all have a simple structure.

How many eyes are in the scorpion, and where are they located on the body? Some species have adapted to live with one pair. The maximum number is 12 simple eyes. And one of their pair (obviously larger) is in the center and plays the main role. The rest are located on the sides and lower along the perimeter.

Catching the victim with front claws, the scorpion raises it above his head and pierces the point of the sting that is on the end of the tail. How many eyes do the scorpion control this process? Presumably, the steam on top is, to a certain extent, responsible for this. Whether simple simple eyes are complicated by the visual system (evolved for improvement) or by its simplification (they did not have time to completely atrophy), it is impossible to ascertain for certain.