Whale sharks have eyeballs covered in small teeth

Marine biologists in Japan say whale sharks have eyeballs covered in tiny teeth, in a unique discovery of this huge but gentle aquatic species

Teeth are typically used to describe our upper canines.but new investigation published in PLOS One describes the teeth of one eye literal type

Marine biologists from Japan’s Okinawa Churashima Research Center have found Whale sharks have eyes covered with dermal denticles or modified teeth. These small structures represent a previously unknown form of eye protection, which serves as a kind of armor to protect against the elements, according to new research.

Whale sharks are the largest sharks, and they grow while 59 feet (18 meters). These giants are harmless to humans, feeding mainly on plankton and the occasional fish.

Whale sharks, unlike other species of sharks, do not have eyelids. Also, her little eyes are located at the corners of her square. heads, exposing their onlookers to possible damage. That’s where the protective eye denticles come in.

Sharks have dermal denticles in other parts of their bodies. These marine animals do not have scales like other fish, but they do have placoid scales, which are made of dermal denticles. These modified teeth, with their hard enamel, provide sharks with armor-like protection, but they also work to reduce friction in the water, Help Sharks swim with speed and stealth.

For the new study, the researchers analyzed the eyes of live and dead whale sharks from aquariums in Japan and the United States. It is the first detailed investigation of whale shark eyes and possible protection mechanisms.

The researchers found a treasure trove of dermal denticles distributed on the surface of their eyes, particularly around the iris. Nearly 3,000 eye denticles were found in a single eyeball. Calling them teeth is not an exaggeration; When looking at the dermal denticles under a microscope, these structures actually resemble teeth. Or as the researchers described them, they looked distinctly “oak leaf-like,” in contrast to the three-pointed dermal denticles found on placoid scales.

“Covering the surface of the eye with denticles in the whale shark is likely useful in reducing the risk of mechanical damage to the surface of the eye,” the researchers concluded in the study. According to the study, other sharks don’t seem to share this characteristic, making armored eyes unique to whale sharks.

But that was not the only protective mechanism detected in the eyes of whale sharks. As new research shows, these giant fish also have a rare ability to tuck their eyeballs into their basins. The “retraction distance was calculated to be about half the diameter of the eye, which is comparable to that of other vertebrates known to have highly retractable eyes,” such as bottlenose dolphins, according to the document. Along with the eye denticles, this retraction ability also serves to protect vulnerable eyes from whale sharks.

Dermal denticles in sharks appear to be an adaptive traitBut teeth sometimes appear in places where they shouldn’t, at least in humans. This is known as a teratoma, in which a tumor is found to contain different types of tissue, including teeth and hair. In teratomas, ectopic teeth, as they are called, tend to appear in the ovaries, and can be safe remote during surgery