Sharks Changing Colors – How?

Scientists from the City University of Hong Kong have discovered that blue sharks can change color, thanks to special tiny structures in their skin. These sharks are known for their beautiful, shimmering blue color, often described as metallic or oceanic blue, which is very rare in nature, and now we know why.

Their skin has tiny crystals that reflect blue light and melanosomes that absorb other colors. These two parts work together like small mirrors and dark filters to create the shark’s shiny blue appearance. The scientists studied the skin on the sharks’ fins using powerful, high-resolution microscopes and ran computer models to see how the skin behaves in different situations. They found that when the shark swims deeper in the ocean, the water pressure pushes the crystals closer together, which makes the shark’s color appear darker.

Even small changes in the water, like humidity or pressure, can change how the shark looks. This helps the shark blend in better with the ocean by matching the color of the surrounding water. It’s a clever way to stay safe from predators like larger sharks or killer whales, or to sneak up on prey such as squid, small fish, or crustaceans. Professor Dean, one of the lead scientists in marine biology, said that this mix of color reflectors and light absorbers packed closely together has never been seen in sharks before.

This type of color-changing skin mechanism is similar to others seen in animals like chameleons or octopuses, but it is new for sharks. The discovery not only helps scientists understand more about how sharks live and survive in the ocean, but it may also lead to innovative inventions, such as clothes or gear that can change color just like a shark’s skin. This research is an exciting step forward in both biology and technology.