Greenland Sharks Are Dog Slow — So How Do They Eat?
Greenland shark part of a drawing in ‘Male Narwhal or Unicorn. Greenland Shark.” In: “An account of the Arctic regions with a history and description of the northern whale-fishery”, by W. Scoresby. 1820. Source http://www.photolib.noaa.gov/library/libr04
We’ve barely explored the world’s oceans, but when it comes to marine life living in the harsh conditions at the poles where few scientists and explorers can spend time, we are constantly being surprised by what we’re discovering. The Greenland shark — the largest shark in the dogfish family — is no exception. It’s slow — really slow — so scientists asked the logical question: “If it’s so slow, how does it catch prey?” The BBC reports on a recent study.
Data-logging tags revealed that Greenland sharks “cruise” at 0.34m per second – less than 1mph.
The study showed that, even when the languid fish embarks on a burst of speed in order to hunt, it is far too slow to catch a swimming seal.
Since the species is known to eat seals, the scientists think it probably “sneaks up on them” as they sleep under the water.
The Greenland shark was already known to be the world’s slowest swimming shark, but its sluggishness surprised the scientists.
More Reading:
- Lights, Camera, Walrus! Ocean Doctor interviews Adam Ravetch
- These sharks are so slow they can only catch you if you’re asleep
- The Greenland Shark, too Slow to Hunt? | Blue Line
- Sneaky sleepers catch snoozing seals – ecoscene
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