Discover the mystery of 'invisible' sharks

With the ability to glow and mingle with water colors, some sharks become completely invisible to prey and enemies.

The British have a proverb: 'The Earth is a sphere, not a cube, so you have no corners to hide' . It is the same in open waters. Every creature often faces the dangers of survival.

However, some shark species have solved this problem by becoming "invisible" to prey and enemies, according to new research published in Experimental Marine Biology and Ecology.

According to Dr. Julien Cleas, the study has counted more than 50 different shark species, equal to 10% of the total number of sharks capable of glowing and creating phishing scams: by glowing, they are nearly invisible. , creating the possibility of camouflage merging with water color.

Scientists have focused on a particular glowing shark, the vampire belly shark, nicknamed the gulf hunting ghost. The light emitted by the shark comes from the phosphor that lies inside their bodies.

The picture shows the glowing ability of the spotted shark.

The study was conducted: spotted sharks in Bergen Bay (Norway) were taken to Espeland Ocean Station. This area has the same conditions as their habitat: cold and dark aquariums.

Initially, scientists measured the intensity of each shark's glow. A few days later, this was repeated after they placed lighting fixtures on the aquarium to check their reaction to light.

As soon as they are put into the aquarium, most sharks automatically emit light, lasting for a few hours. The measured light spectrum is similar to the light they emit in deep water at home.

They have the ability to manually adjust the level of glow depending on the change of outside light. The ability to obtain by using eyes and small glands in the brain to monitor information about light shining from above.

In addition, the mouths of most sharks lie in the lower part, according to the reverse light principle, so enemies or prey are unlikely to notice the difference. This allows sharks to catch prey like molluscs or fish without being detected.

Cleas commented: 'Since many of their enemies have an upward eye, the shark uses camouflage in the mid-range waters (300 - 1,000 m below the surface). "

In addition, the ability to glow is also used by these sharks to attract heterosexuals. Dr. Claes said: 'Communication is also a function of the ability to glow. Some parts of the animal become brighter at close range, especially the pelvic part, where the genital organs are located '.

Thanks to its unique ability, glowing sharks have a higher survival ability than other species, because of avoiding the pursuit of enemies as well as easy access to prey.