Weird Wildlife Wednesday: Shark Week Sucks
(Content warning: sharks. Jay, you should probably stop reading now)
The Discovery Channel makes all kinds of things up during Shark Week which means you probably have a shark-shaped gap in your soul. To remedy this, I’ve made you up a list of real weird sharks that actually exist.
Frilled sharks are deep sea sharks that are eel-like and grow up to 2m long. They are one of the few shark breeds that have mechanoreceptive hair cells (the little fibers in the gills that collect oxygen) directly exposed to seawater. This is thought to be a primitive trait that may heighten sensitivity between the shark and its prey in the water.
This shark is named for its unusual feeding strategy. Glowing cells on the underside of the shark called photophores attract large fish from below, which approach and are then unexpectedly bitten. The cookiecutter shark uses its lips to create a seal and pointy teeth to latch on to the prey. Once it is firmly attached it spins around and removes a perfectly round hole from the prey’s body.
Even I have trouble finding this one cute. This shark electrodetects its prey through a sensory system called “ampullae of Lorenzini.” The large protruding jaws of the Goblin Shark retract and protrude, they are relaxed when protrouded. The shark swims around with the jaws in tension and uses the jaws as a catapult when it is time to feed.
Ghost Sharks, like lungfish and platypuses, do not have stomachs anymore thanks to pesky ol’ evolution. These genetic changes apparently occur in animals that lack the genes that can maintain high acidic zones in their digestive system. Digestion is facilitated through the rest of the digestive tract in the absence of an acidic stomach.
The least visually distinct shark on this list is probably the most interesting. The rare and huge Greenland shark unusually lives in northern latitudes and is the only known shark species that tolerates Artic temperatures all year. In summertime these sharks even move to deeper and colder waters, preferring temperatures from 1°C to 10°C (I still won’t convert for you). This shark can grow to over 6m, sometimes even larger than the great white shark. Some scientists have estimated the lifespan of this shark to near 200 years, after a tagged shark was shown to have only grown 6cm in 16 years. At this rate, the largest observed species would be over 200 years old making it one of the oldest vertebrates on earth. The Greenland Shark also has poisonous flesh- the sharks contain trimethylamine which protects them from the cold. This chemical also causes effects similar to alcoholic intoxication and eventually death. The meat can be prepared safely in a complicated process that involves burying the flesh and then letting it dry. The video below explains how this “delicacy”, called Hákarl, is created.
What I want to know is how they figured out that THIS exact process for this exact number of days works. I am glad I wasn’t the person who had to taste test the rotten meat and then die because it was still poisonous.
I guess now it is time to go enjoy the entire week I’ve just saved you.