Scientists Finally Realize The Reason Why 'Great White Sharks' Are Not All White — and It's a Massive Advantage
Years of examination have proven that creatures gain several evolutionary advantages to survive in their habitats. "Great White Sharks" have followed a similar trajectory, according to the IFL Science. One of their adaptations seems to be camouflaging. It allows them to target their prey efficiently, as it is visible in the varying colors of its body and belly. The color arrangement on the great white sharks is such that, under natural light, people can get confused about what exactly they are looking at. In this way, they do not come near the sharks with their guards up. This situation allows sharks to go for the 'kill' in the face of less adversity. Certain evidence also indicates that these sharks not only use their natural color in hunting, but also control their appearance for the purpose.
Bizzare Name
"Carcharodon carcharias" is popularly called the great white shark. Many people may therefore expect these creatures to be all-white, but that is not the case. Instead, they are mostly grey with just a white belly, as it is an important feature, and they are named after this quality. The color arrangement on the great white sharks is an example of countershading, according to the Aquarium of the Pacific. This phenomenon allows the creatures to blend in with the darkness of the deep ocean as well as the sunlight-lit waters from different perspectives.
Essentially, for viewers looking down on these creatures, the great white shark seems to be one with the darkness due to its grey color. On the other hand, when viewers are looking up at them, their white bellies allow the creatures to become one with the sunlight waters near the surface. Hence, no matter the depth, these creatures can camouflage themselves from their prey. Considering that great white sharks hunt on the entire marine ecosystem, this flexibility goes a long way.
Changing their Color
Great white sharks do not just have countershading in their arsenal of evolutionary advantages, according to National Geographic. They can also change their color for an advantage in their habitats. It was noted in 2022 off the coast of South Africa. A team of experts placed a seal decoy behind a ship to attract sharks. The aim was to monitor sharks in the area with the help of a specially designed color board, carrying black, white, and gray panels. One of the sharks in this examination had a visible abscess on its jaw, which became easy to track. Researchers became intrigued because the shark was captured exhibiting both dark gray and much lighter gray shades in photographs.
Interaction with Hormones
For further examination, the team took a small tissue sample from the shark and treated it with several hormones that were known to occur in sharks. Researchers noted that when the tissue interacted with adrenaline, the melanocytes, skin cells with pigment, contracted in size and turned lighter in color. Another hormone, melanocyte-stimulating hormone (MSH), caused the cells to disperse and become darker. "We wanted to trick these shark cells into thinking they were getting some kind of stimulus, like the sun or an emotional stimulus [such as seeing potential prey] to see if we could get them to change and become lighter or darker," said Gibbs Kuguru, a shark scientist at Wageningen University and Research in the Netherlands.
"So we tested it, and not only did it work, but it was a swinging success," added Kuguru. Researchers want to examine more sharks before making any assertions, as they have yet to understand why these color changes are taking place. Some believe ultraviolet (UV) protection could be a reason, but the involvement of hormones like adrenaline hints at hunting also being a cause. "[T]his could potentially be something that they themselves are manipulating to get darker or to get lighter," Michelle Jewell, who studies great white shark behavior at Michigan State University Museums, shared. "It would make a lot of evolutionary sense."