The Greenland Shark

The Greenland shark isn’t the type of predator that often gets mentioned on TV shows or dramatized in movies. However, this giant, slow-moving resident of the North Atlantic may deserve the spotlight every once in a while for its potentially record-setting size and lifespan.

Photo: Discovery

Also known as sleeper sharks, the largest Greenland shark ever recorded was 21 feet long. However, it is believed that these sharks can exceed 24 feet in length. If this is the case, the Greenland shark would be the largest predatory shark in the world, even surpassing the great white; only filter-feeding basking sharks and whale sharks are larger.

Part of the reason this shark is so difficult to study is because of the extreme depths at which it lives. Greenland sharks have been recorded at depths of more than 7000 feet, and usually only come to the surface near ice floes in the winter.

Greenland sharks are thought to be ambush predators, pinning and consuming a large variety of bottom-dwelling fish and crustaceans. They are also known to be scavengers, and like many sharks will eat just about anything, living or not, that they can find. Despite their size, Greenland sharks are notoriously sluggish by nature and are not considered dangerous to humans.

The exact lifespan of the Greenland shark is uncertain. However, scientists have determined that they grow at an extremely slow rate of less than one centimeter per year. If this is the case, fully grown adults specimens may be well over 200 years old, making this shark the longest-lived vertebrate on the planet.

Sharks from Small to Huge

As I mentioned yesterday, this week is all about the celebration of sharks. And while tiger sharks and great whites may get most of the press, they are just a small part of the 400+ species' of these amazing animals. Today I thought I would show you the two bookends of the Selachimorpha (shark) superorder size-wise; the dwarf lanternshark and the whale shark.


Dwarf lanternshark - Illustration by Tambja

 The dwarf lanternshark is the smallest known shark species in the world. Found only in the southern Caribbean Sea near Venezuela and Colombia, this rare species of dogfish shark reaches a maximum length of  only eight inches and lives about 1,000 feet below the surface.



Whale shark - Photo by Zac Wolf

 On the other side of the spectrum is the massive whale shark; not only the largest shark but also the largest fish species in the world. Whale sharks of up to 41 feet in length have been confirmed, and they can weigh in excess of 79,000 pounds. In other words, they are as long as a city bus and weigh as much as 25 automobiles. Despite their massive size, whale sharks are not vicious killers. They are filter feeders and subsist mainly on a diet of plankton and small fish. They swallow massive quantities of water containing their prey when they feed, expelling the excess liquid through their gills and swallowing the leftover plankton.