Most people think of sharks as bloodthirsty predators. They are animals capable of sensing blood from miles away, stopping at nothing to hunt their prey, even if said prey is a human, *gasp*. These preconceived notions come largely from Hollywood films like 'Jaws', where the best way to sell tickets is to create an image of a shark so terrifying you want to stay out of the water for the rest of your life. In reality, sharks don't actually destroy fishing boats or tear apart diving cages. There are sharks of all types, and I happened to stumble across one of the more obscure creatures while browsing Twitter.
The Greenland Shark is unique. It lives deep in the ocean, over 2,000 meters deep! Water that far down is very cold, and can even dip below freezing. Of course, due to the high pressure at that depth, the water doesn't turn to ice, even though the temperature is below freezing. To prevent the shark's body from freezing in these waters they have adapted to have high levels of trimethylamine oxide in their skin. This chemical helps them deal with the osmotic pressure and the freezing temperatures. It also comes with an added bonus, it is poisonous when consumed. Any predator that takes a bite out of this shark will undergo neurological distress which can be fatal. This is especially useful for the Greenland Shark because they are very slow moving, making them somewhat easy targets.
If that wasn't weird enough, many of these sharks exhibit a symbiotic relationship with Ommatokoita elongata, a parasite that latches onto and feeds off of the eyes of the shark. But instead of harming the shark (which most people would think is the primary concern when your eyes are being eaten) the sharks can benefit from this parasite. The parasite is slightly luminescent, and attracts fish to the shark. The shark, being used to living 2,000 meters beneath the sea, is well adapted to the dark and can sense the fish using its other senses.
I hope my brief description of the Greenland Shark has helped to improve people's conceptions of sharks in general. While there are some sharks that aggressively hunt their prey, the Greenland Shark offers a different perspective. I find this to be an important topic because all around the world sharks are hunted for their fins. Many people aren't concerned because they have negative opinions of sharks, but the truth is that these animals are fascinating and deserve to be respected. The more awareness and interest that is displayed towards sharks the more funding will go into studying them and protecting them, so even if you have a mild interest in these animals, let everyone know!
Posted By: Tim Daly (1)