According to a new study by a group of Japanese scientists, whale sharks – the largest fish on the planet – can see clearly even in dark deep-sea environments due to a mutation in the retina. of them.

This mutation is also the cause of night blindness, also known as night blindness, in humans. This is a type of vision impairment that many people experience at night or in low-light environments.

Research shows that gene mutations in whale shark eyes activate visual pigments that sense blue light – the only color that shines into the deep sea, based on temperature changes. Whale sharks often swim near the sea surface to eat plankton, but they also dive into deep waters to depths of nearly 2,000 m and much of their biology remains a mystery to humans.

To better understand how organisms can see in both bright surface waters and the dark environments of the deep sea, researchers focused on analyzing rhodopsin – a protein in the eye’s retina that allows see in low light environments. They discovered that the protein rhodopsin, which is normally sensitive to green light, had mutated in whale sharks to become more sensitive to blue light. This change in amino acid composition helps whale sharks see better in low-light environments on the seafloor, but similar changes in humans lead to night blindness.

Professor at the National Institute of Genetics Shigehiro Kuraku – a scientist participating in the study, said that although rhodopsin in whale sharks decomposes when exposed to heat, it still works effectively in the cold waters of the deep sea. Whale sharks’ blue light-sensing pigments adapt to temperature.

The study, conducted by scientists from the National Institute of Genetics, Osaka Metropolitan University, the Okinawa Churashima Foundation, and the RIKEN Biosystem Dynamics Research Center, was published in the journal of the National Academy of Sciences. ./.