The eyes of wide bodied bigeye crabs are particularly large, does such a big eye have any effect?

The wide-bodied bigeye crab is an animal of the genus Bigeye in the family Sand Crab. It is distributed on the west coast of North Korea, Japan, Taiwan Island and Guangdong, Fujian, Zhejiang, Shandong, Bohai Bay, Liaodong Peninsula and other places in Chinese mainland, and its living environment is seawater, and it is common to live in the mudflats near the sea or at the mouth of the river. Wide-bodied bigeye crabs are in the family Sand Crabs.

It is an animal of the genus Bigeye Crab, which is distributed in Guangdong (Hainan Island), Fujian, Taiwan, Zhejiang, Shandong Peninsula, Bohai Bay, Liaodong Bay, Liaodong Peninsula, North Korea, and Japan.

The cranophorax is about 2 5 times as wide as its length, the anterior half is wider than the posterior, and the surface is granular, with males having more pronounced granules than females. There is a transverse groove between the hepatic and branchial regions and the gill region. The stomach area is nearly square, and the heart area is transversely rectangular.

The forehead is narrow and prominent, the eye socket is broad, the dorsal margin is granular, and the abdomen is green with a row of serrations. The eye stalk is elongated. The lateral margin has long bristles, and the anterior lateral margin is divided into 3 teeth, the outer socket teeth are narrow and sharp, almost conjunct with the second tooth of the triangle, and the third tooth is small and distinct.

The male chelicera is long, with 1-3 teeth in the last half of the dorsal margin of the long joints, 2 teeth on the anterior ventral margin, and granules on the posterior ventral margin.

The inner terminal angle of the carpal segment has 2-3 teeth, the metacarpal segment is very long, and the dorsal margin has 6 dentate protrusions. The space between the two fingers is large, the movable fingers are almost perpendicular to the metacarpal segment, the inner edge has unequal obtuse teeth, the immobile point is curved inward, and the middle of the inner margin has a tooth-like protrusion. Females are short.

The third pair has the longest steps, and the fourth pair is the shortest. The dorsal margin of each footcut has long bristles. Males have a blunt triangular abdomen, while females have a large round abdomen that covers almost the entire thorax.

The cephalothorax was 17 5 mm long and 4 0 mm wide.

Observe your surroundings and prevent them from being caught by predators.

It is beneficial for bigeye crabs to better find natural enemies and food, which is convenient for themselves.

In the living environment, you can better see predators or prey.

The pupil is similar to a convex mirror, which expands the field of vision and better detects the presence of enemies.

Have a larger visual space and be able to better perceive the things around you.

In order to survive, evolved to quickly find natural enemies.

You can better observe the surrounding environment and capture the food.

It helps it to find natural enemies faster.

A wider range of viewing angles can be seen, making it easy to hunt and spot prey.

In order to be able to detect the enemy faster, avoid danger in advance.

Crabs have two eyes, both of which are compound eyes, each consisting of hundreds of single eyes. The structure of the crab's eyes is very special, like two small balls, and the back of the small ball seems to carry a handle, and this handle can also rotate freely. Since their eyes can be rotated freely, they can observe any direction they want to see, and the direction they can see can be said to be all-round and without blind spots.

Crabs are a type of crustacean, and we can often see crabs and can easily observe them. Although crabs are not very advanced animals, they do have some basic body structures. For example, crabs have eyes, and they are relatively obvious, so it is easy to observe them if you observe them.

The eyes of crabs, like the eyes of other animals, are used to see things, and their eyes play a very significant role in their various life activities.

As mentioned above, crabs have eyes. Judging by the numbers, crabs have two eyes. Although the number of eyes of a crab is two, it is different from the two eyes of humans and many animals, because the eyes of crabs are compound eyes, which are made up of hundreds of single eyes.

The structure of these two compound eyes is quite special, the shape is like two small balls, but the back seems to carry a handle. Moreover, the handle can be rotated freely. In this way, the crab will move the direction of the handle at will if it wants to observe which, and turn its eyes to a specific position, so that you can see the direction and position they want to see, so it can be said that the direction observed by the crab is all-round, and there is no dead end.

In fact, in real life, crabs often bury their bodies in the mud and sand, and then only show their eyes, so that they can observe the movement around them at any time.

The eyes of crabs are compound eyes and have stalks. The eye of a crab is a stalk that grows on the stalk, and the base of the stalk can be moved, and the crab can see in all directions. When a crab is hiding in the sand, it can only keep its eyes out and look around.

The crab's eyes can be retracted freely, and there are two eyes, both of which are compound eyes, like two swinging balls, which can rotate freely.

Each eye of a crab is made up of a number of small eyes, sometimes standing up, sometimes flat, like folding binoculars.

The eyes of crabs are related to the way crabs walk, and the latent life is related, and the vast majority of crabs walk horizontally, which can avoid the occlusion of the cephalothorax to the line of sight.

Grows on antennae.

Crabs: Animalia, phylum Arthropods, Crustacea, Mollus, True Molluscs, Decapod, Ventral Embryo, Brachycda. It is a crustacean, its body is protected by a hard shell, and it breathes by its gills.

Taxonomicly, it is the same animal as shrimp, lobster, and hermit crab. The vast majority of species of crabs live in the sea or near the sea, but some inhabit freshwater or land. They rely on female crabs to give birth to baby crabs, and each female crab lays a large number of eggs, which can reach more than millions of eggs.

Crabs rely on the geomagnetic field to determine direction. The genetic material of such organisms is complex and highly varied, often as many as more than 100 pairs.

Most species of crabs walk sideways, and when the stalks are raised, the two eyeballs can reach out to the left and right sides of the body, thus avoiding the obstruction of the view by their cephalothorax. By taking advantage of the wide range of compound eye imaging, it not only takes into account the field of view in front of it, but also makes it move to the left and right directions or even the side and back without any blind spots on the line of sight.

In the Jiangnan area, hairy crabs have been a delicious food that people have loved since ancient times. The official name of the hairy crab is the Chinese mitten crab because of the soft hairy hairs on its two claws. If you look closely at a live hairy crab, you'll notice that its eyes are sometimes upright, sometimes flat, like a pair of folding binoculars.

It turns out that hairy crabs have very special eyes. The stalk eye, as the name suggests, is that the eye grows on the stalk. Not only hairy crabs have stalk eyes, but all species of crabs also have stalk eyes, and the base of the stalk has movable joints that allow the eye stalk to be both erect and down.

So why do crabs have a pair of stalk eyes?

First of all, it has to do with the way crabs walk. With the exception of a few crabs (such as monk crabs) that can walk upright, the vast majority of species of crabs walk sideways. At this time, if there is an enemy situation on the left and right, by the time it turns around, I am afraid it will already become someone else's food.

But with the stalk, the two eyeballs can reach out to the left and right sides of the body, so as to avoid the obstruction of the view of the head and chest. By taking advantage of the wide range of compound eye imaging, it not only takes into account the field of view in front of it, but also makes it move to the left and right directions or even the side and back without any blind spots on the line of sight. So, if you want to talk about the crab's eyes, it's really wonderful, when you feign to attack its front, side or even side back, its eyes will stand straight up, stretch out to the sides of the body, lock on to the target, waiting to deliver a fatal blow to the intruder.

Secondly, it has to do with their latent life. For example, the sand crab that inhabits the beach has two long eye stalks, which stand up like two matchsticks. Sand crabs often bury their entire bodies in the mud and sand, leaving only their two stalks upright and exposed, like periscopes, vigilantly observing the movements around them.

The eyes of crabs, like insects, are compound eyes, and each eye is composed of many small eyes, which are photosensitive and imaged on the retina, and finally transmitted to the brain through the optic nerve and finally stitched together to form a complete image. The compound eye is a protruding spherical body, and the field of view is inherently wider than that of a human eye; Coupled with the help of the eye stalk, it is really a tiger with wings. When the eye handle is erected, the crab is like two lookout posts, and you can see the six roads; When you fall, you can even hide the handle in your eye socket.

If the eye is damaged due to carelessness or accident, it can grow new eyes. If the eye stalk is cut off, a useful antennae will grow into the eye socket to compensate for the lack of eyes.