By: Amanda Kelley
Sharks are some of the most athletic and precise predators in the ocean. With just a flick of the tail and a flash of teeth, these fish have adapted killer instincts and sensory traits to become the skilled hunters of the sea. How could you not be impressed? Just look at them in action:
Image source: giphy.com
But, as it is across the animal kingdom, there are always exceptions to the perceived norm. If you’re familiar with sharks, then you probably know about the whale shark and the basking shark.
These two species of shark adapted a large body size and utilize an almost passive filter-feeding method (similar to some whales) instead of active hunting. But what if I told you that there is another shark out there that is so very passive that it has to wait until its prey is asleep before even attempting to attack?
I’m talking about the Greenland shark, and boy if you thought YOU were lazy, this fish will show you what it means to be lackadaisical… but maybe later… tomorrow, if he’s not too tired…
Reaching blistering cruising speeds of less than 1mph, the Greenland shark is known for being the slowest fish in the ocean. It takes seven seconds for one full sweep of its tail to propel it forward. These guys are basically the toothy sloths of the northern sea.
Who, me?
Image source: giphy.com
The arctic waters that these sharks inhabit average about 2°C, so their sluggish behavior can be attributed to the energy cost of swimming in their near-freezing surroundings. However, unlike the whale shark and basking shark, these fish are still active hunters. How are these sloth sharks possibly hunting anything? There can’t be many other animals swimming around less that one mile per hour…
For the Greenland shark, it looks like it’s “work smarter, not harder.” Researchers have proposed that these sharks hunt by sneaking up on unsuspecting, sleeping seals.
Arctic seals sleep in the water in order to avoid the potential of a polar bear attack, but it leaves them vulnerable to the Greenland shark. Evidently, the sleep that the seals enter is so deep that one researcher was only able to awaken one after approaching and poking a seal that he believed to be dead!
Although scavenging of the seal meat is also a possibility, researchers have not ruled out the hunting prowess of this slow-moving predator. Looks like lazy works in this case!