Latest news with #nanostructures
BBC News
11-07-2025
- Science
- BBC News
Blue sharks can change colour to camouflage say scientists
Blue sharks get their name from being, well, blue! But did you know that's one of the rarest colours in the animal kingdom? Scientists at the City University of Hong Kong looking at what makes this fish this colour found it's down to tiny nanostructures in their skin, which act as blue reflectors. Other structures also absorb other types of light - which help to produce the shark's characteristic colour. But not only that, the sharks' skin can change colour too. The team say a multi-functional design like this "as far as we know, hasn't been seen before". Read on for more. The research shows the secret to the blue shark's colour lies in the tooth-like scales on its guanine crystals act as blue reflectors while another structure, called melanosomes, absorb other wavelengths of colour. Professor Dean from the City University of Hong Kong said: "These components are packed into separate cells, reminiscent of bags filled with mirrors and bags with black absorbers, but kept in close association so they work together."When you combine these materials together, you also create a powerful ability to produce and change colour." The researchers had to look at a shark's fin really closely under lots of powerful microscopes. They used simulations on a computer to recreate and understand the structures under different Dean continued: "Very fine scale alterations resulting from something as simple as humidity or water pressure changes could alter body colour, that then shape how the animal camouflages or counter-shades in its natural environment." The research suggests even something as simple as swimming deeper in the ocean could make the sharks look a deeper colour of blue as the guanine crystals are forced closer together with the increased pressure from the water.
The Independent
11-07-2025
- Science
- The Independent
Scientists discover shark that changes colour like a chameleon
Unique structures on the skin of the blue shark suggest it may be able to change colour like a chameleon, according to a new study. The study, presented this week at the Society for Experimental Biology conference in Antwerp, reveals tiny nanostructures in the skin of the blue shark, Prionace glauca, that produce their colouration. The secret to the shark's colour lies in the pulp cavities of the scales that armour the skin, known as dermal denticles. 'Blue is one of the rarest colours in the animal kingdom, and animals have developed a variety of unique strategies through evolution to produce it, making these processes especially fascinating," Viktoriia Kamska, a researcher who participated in the study, said. Crystals of the molecule guanine within the pulp cavities act as blue reflectors. In addition, cell components containing the pigment melanin absorb other wavelengths to produce the shark's characteristic colour. 'These components are packed into separate cells, reminiscent of bags filled with mirrors and bags with black absorbers, but kept in close association so they work together," Dr Kamska explained. The melanin collaborates with guanine crystals of specific thickness and spacing to enhance the shark's colour saturation of the skin. "When you combine these materials together, you also create a powerful ability to produce and change colour," Mason Dean, another researcher, said. "What's fascinating is that we can observe tiny changes in the cells containing the crystals and see and model how they influence the colour of the whole organism.' The research was made possible by advanced imaging techniques to characterise the form, function and architectural arrangements of the tiny colour-producing structures. "We started looking at colour at the organismal level, on the scale of meters and centimetres, but structural colour is achieved at the nanometer scale, so we have to use a range of different approaches," Dr Dean said. Researchers then used computational simulations to confirm which structural parameters of the tiny skin structures were responsible for producing the observed appearance. They showed that this mechanism of colour change could also be driven by environmental factors that would affect the guanine crystal spacing. "In this way, very fine-scale alterations resulting from something as simple as humidity or water pressure changes could alter body colour, which then shapes how the animal camouflages,' Dr Dean said. When the shark swims deeper, for instance, more pressure acts on the skin, causing the guanine crystals to be pushed together and darken the shark's colour to better suit its surroundings. The mechanism by which these tiny structures behave may also be changing the shark's skin colour. "Such a multi-functional structural design – a marine surface combining features for high-speed hydrodynamics and camouflaging optics – as far as we know, hasn't been seen before,' Dr Dean said.
Yahoo
11-07-2025
- Science
- Yahoo
Blue Sharks May Be Secret Chameleons, Scientists Discover
The blue shark (Prionace glauca) might be more than its name. Scientists investigating the sleek ocean predator's skin discovered nanostructures that not only produce its signature hue, but also potentially let it change color like a chameleon. Animals produce their colors in various ways. Some rely on pigmented cells that reflect a color by selectively removing wavelengths from ambient light, while others have microscopic light-scattering structures that build or remove select wavelengths – think peacock feathers. A rare few can tweak their color-coding features in response to their surroundings, by modifying how wavelengths are absorbed or scattered. Now it's been revealed that the blue shark has that color-morphing ability, in a new study led by scientists at the City University of Hong Kong (CUHK). Related: As their name suggests, blue sharks generally have dark blue coloration on their backs and lighter bellies. Their skin is lined with tooth-like scales called dermal denticles, and inside these are pulp cavities that play a key role in producing color. The researchers examined these denticles using optical and electron microscopy, spectroscopy, and other imaging technology. They found that the pulp cavities contain guanine crystals, which reflect blue light, and tiny little sacs of the pigment melanin that absorb other colors. "These components are packed into separate cells, reminiscent of bags filled with mirrors and bags with black absorbers, but kept in close association so they work together," says Viktoriia Kamska, molecular biologist at CUHK. On closer inspection, the team found that these structures don't just put the "blue" in blue shark – they could potentially respond to the animals' environment to change their colors. Narrow spacing between layers of guanine crystals gives the sharks the blues, but if those spaces widen, they can potentially turn shark skin green or yellow. Chameleons also get their color-changing abilities by shuffling guanine crystals around. In the shark's case, this could naturally boost their camouflaging capabilities. If they dive deeper, for instance, the greater water pressure should push the crystal layers closer together, darkening their skin to match the darker waters. At this stage, the effects have only been simulated, but the team plans to study how the mechanism might function in the natural environment of wild sharks, to gain a deeper understanding of how nature engineers color at the nanoscale. The research was presented at the Society for Experimental Biology Annual Conference in Belgium. Scientists Just Debunked 'Earth's Oldest Impact Crater' 'Chimpfluencers' Are Sticking Grass in Their Ears And Butts in Latest Viral Trend New Cell Discovered in Pythons Allows Them to Completely Digest Bones
