(A study has shown for the first time) that starfish use primitive eyes at the ends of their wings to direct their environment with their eyes. The study was headed by Dr. Anders Garm at the Marine Biology Department of Copenhagen University, Denmark. Research has shown that starfish eyes form images and can be an important stage in eye evolution.
The researchers moved the starfish with and without eyes from their food-rich habitat, a coral reef, and brought them to the seabed containing sand located one meter away from their location, where They can starve to death. They tracked the behavior of starfish from above the water and found that while starfish have intact eyes moving toward coral reefs, those who do not have their eyes crawled sporadically. Of course.
Dr. Garm said: 'The results show that the starfish's nervous system must be able to handle visual information, which leads to a pronounced underestimation of the ability to search in circles and Something that has dispersed the central nervous system of echinoderms.
Analyzing the morphology of photoreceptors in the starfish's eyes, the researchers further confirmed that these receptors form an intermediate state between two known large groups of photoreceptors: receptors Rodent and cilia, in which the starfish has both micro-hairs and modified rod forms.
Dr. Garm adds: 'From an evolutionary point of view, this is very interesting because the morphology of the starfish eye corresponds to the optical quality (image quality) that is close to the primordial theory. in the eye's evolution when the image information first appears. In this way, it can help clarify what is the first task of adjusting this important step in visual evolution, namely moving toward the preferred habitat using fixed objects that have Large size (in the case of this study is coral reef) '.
The most famous starfish known to have a double eye at the tip of each of its arms, except for the lack of real eyes, like the arthropods of arthropods. Although the species has been known for about two centuries, no visual behavior has ever been recorded before.