An epaulette shark wiggling its way up the beach. It's been known to use its unique form of locomotion to crawl its way from tide pool to tide pool in search of food. - Courtesy of mrpbps CC BY 2.0
SHARKS have a bad reputation, no thanks to a certain movie from back in 1975, and have long been vilified as monsters from the deep.
But is it true that some sharks can walk on land?
Verdict:
TRUE
Now before you start imagining a great white shark commando crawling its way up the beach it would be best to temper your expectations.
While it is true that great whites intentionally beach themselves to catch seals, they never go too far past the water line else they wouldn't be able to push themselves back into the ocean.
They do have a more diminutive cousin that actually is able to not only survive for hours out of the water, but even purposefully "walk" from one point to another.
The epaulette shark, so named for the big eyespots on its 'shoulders' that somewhat resembles the epaulettes worn by the uniformed services, is a smallish reef shark fairly common in southern New Guinea and northern Australia.
It is usually less than a metre in length and is light brown in colour and aside from its two prominent eye spots, it has other smaller black spots along its sides and back.
The shark has a curious way of getting around, as instead of swimming it prefers to crawl across the sea bed using its fins as feet, using a gait similar to that of a salamander.
Not only that, as its usual habitat is very close to the shore line and in tide pools, it very often finds itself stranded on land.
This doesn't prove to be a problem for the shark as it has evolved to tolerate hypoxia (extremely low levels of oxygen in the blood) and has been recorded to survive up to two hours out of water.
Its preferred locomotion also helps it on land as it can crawl just as well out of the water as within it and has been known to waddle up to 30m on land.
References:
1. https://www.eurekalert.org/news-releases/635251
3. http://elasmo-research.org/education/ecology/intertidal-epaulette.htm
