What is Eyestalk?

Eyestals are common in molluscs and crustaceans such as crabs, lobsters and snails. Eyestalk is a long, slim pendant that extends from the animal's head and ends with the eye. It can easily move for the animal to look in any direction and can be extended or inserted as you like. He does this by drawing blood to or from the eye. When blood is full, it is prolonged and when the blood is removed, it is inserted.

In addition to providing an extended field of vision, Eyestalk contains different hormones that affect the different aspects of the life of the creature. Experiments have been carried out where the eyeliners were removed from different animals and the removal has influenced much more than just visual ability. Specific hormones and thfunction Eir differ somewhat according to species and gender, but in general hormones relate to the growth and reproductive activities of animals. Because crabs have an exoskeleton, they must melt to grow. Eyestalk of a blue crab affects how much and how quickly these crabs grow by release of hormones that regulate, how often they lose their outer shells.

For spider crabs, Eyestall has a significant impact on the ability to behave. When scientists removed the eyes of some of these crabs, women produced significantly more eggs than those that remained intact. This led the scientist to conclude that this part of the spider's crab produced a hormone that regulates the reproductive activities and the production of eggs.

In other creatures, they perform a different function. Males of certain types of insects, such as fly fishing, use the eye to attract a friend and the larger the male ophthalmology, the more likely it is to be able to reproduce. It can also provide a hosting place for parasites. Amber snail is sometimes seen with a large striped eye eye. This is the result that it has been infected with a parasitic worm that occupies a residence there, causing the eye corner to swell and prevent the snail inserting.