Within the great variety of species that the animal world houses, there are surprising beings of many kinds. One of the parts that stands out the most at first sight of any animal is the eyes. There are those who have them bigger than their brain, as is the case of the ostrich, others that never close them, like fish, and others that don't even have eyes.
Yes, you read it right. There are animals that lack these visual organs and have a really curious appearance. If you want to know which are the animals that don't have eyes, don't take your eyes off this article on our site. You'll have to blink twice to believe it!
Why are there animals without eyes?
For many animals, not having eyes does not prevent them from carrying out their daily activities. In fact, the vast majority of these beings would not need these organs for almost anything in their day-to-day life, since they usually live adapted in very dark places, so that it is likely that the lack of eyes is due to an evolutionary adaptation of their organisms due to lack of need or for their own well-being.
On the other hand, as they do not have vision, these animals often have accentuated other senses, such as hearing, smell or touch, that help them defend themselves or supply themselves with food. Others even have the ability to detect or create electrical activity, so the lack of eyes is not a problem at all.
1. Blind cave crab or jameito
This unique crustacean, also known as jameito, is endemic to the island of Lanzarote, in Spain. Specifically, it is only possible to see this crab in the Jameos del Agua, so its population is in serious danger of extinction.
Color white albino, with a size that barely reaches 2 or 3 centimeters in length and a small carapace of just 1 centimeter, the jameito lives in dark caves where it does not need eyes. Instead, the animal has needed to adapt other senses, such as hearing, to develop without problem in its environment. Without a doubt, this is a very curious and special animal and, for this reason, it is considered a symbol of the island where it lives.
two. Mexican blind tetra or blind cave fish
This fish with light or almost transparent pigmentation is a clear example of animals that do not have eyes thanks to the existence of evolution. From common fish, the blind cave fish evolved until it lost its eyes Given the lack of use that the fish gave to the visual organs, they ended up disappearing with the intention of saving neuronal and cellular energy for other vital activities.
The lack of oxygen and food in the caves and subterranean tropical rivers where it lives in northeastern Mexico led it to do without eyes. In this way, the blind tetra of up to 12 centimeters in length feeds on almost everything it finds, such as insects or crustaceans, without losing energy. Why would it grow eyes in a completely dark environment?
3. Texas blind salamander
The Texas blind salamander is an amphibian about 12 centimeters in length, native to the waters of caves in the state of Texas, mainly Hays County. Its lack of eyes and skin pigmentation is due to the fact that this animal lives in the strictest underground darkness, never coming to the surface at any time. Although its population is very small, its skin, in addition to being especially sensitive, is an ally to avoid being captured, as well as to find food, mainly shrimp and snails.
4. Stygichthys typhlops
If piranhas are already fearsome, now imagine a eyeless piranha Scary, right? Well, this is the case of Stygichthys typhlops, a blind relative of piranhas. This amazing fish lives in Brazil, specifically in the state of Minas Gerais. Despite its lack of vision, Stygichthys typhlops has special sensors that it uses to move, defend itself against predators, and hunt prey.
5. Typhlopids
This type of snake, endemic to tropical regions of Africa, America, Australia and Asia, measures around 25 centimeters and is particularly thin and elongated. A curiosity about this animal is that, Despite losing its eyes due to lack of usefulness, is able to detect light, although it is of little use to him, since he lives in underground burrows.
6. Olm or proteus
The olm, proteus or human fish, named for its similar skin color to people, is a salamander that lives in underground caves in Europe, such as in Italy, Croatia and Herzegovina. As with animals that do not have front eyes, this one is also used to living in the most immense darkness, which is why it has developed its other senses. This curious elongated, flat specimen with short legs can live up to 100 years
7. Sea urchin
Perhaps this is one of the most surprising examples of animals without eyes, because although it was once believed that hedgehogs could see through eyes, it has been discovered that this is not the case. Hedgehogs could actually be defined as “ walking eyes ”. They do not have eyes like what we humans are used to seeing, but they do consist of about 1,500 light-sensitive cell groups, whose information is processed by a network decentralized nervous system specially designed in these beings.
8. Worm
These invertebrates that we have all been able to observe at some time in a park or garden live in moist soil thanks to their ability to breathe through the skin. However, their skin is not only amazing because of the way they breathe, but because of their ability to see. Although earthworms are included in the list of animals that do not have eyes, they are able to perceive light through their skin
Earthworms are sensitive to light and scurry when they perceive it to escape it. This is of great importance for biological research, where the tiny C. elegans worms are already being analyzed for the study of visual diseases. Other curiosities that make earthworms special are their lack of teeth, so these animals suck their food, organic remains, after digging galleries.
9. Leptodirus beetle
This caveman with the huge butt and long legs has no eyes for lack of utility. Although it may seem strange, there are animals, called troglobites, that have adapted to humid, cold environments with little foodand could not survive away from their caves. This is the case of this blind beetle native to caves in Slovenia, Croatia and Italy, but unfortunately not much more information is known about it.
10. Adelocosa
This spider can be seen on the island of Kauai, Hawaii. Accustomed to hearing about tarantulas with 8 or more eyes, it is rare to find one that does not have any. Once again, this eyeless animal has also adapted to its environment by doing away with what it doesn't need and only wastes energy. Its cave home, partially covered in lava and mostly dark and isolated, is why this spider has no eyes.
Now that you know the animals that do not have eyes, do not miss this other article to broaden your knowledge about the animal world: "Animals without bones".
