July 23, 2018
Sharks are known as fierce predators, but there is much more to these fascinating creatures than that stereotype – which, actually, is largely exaggerated. Here at Blue Reef Aquarium Portsmouth we have sharks for you to marvel out so get clued up on these beautiful creatures, ready for your next visit!
In 2016, researchers carbon-dated 28 Greenland sharks and found that one of the females was estimated to be 400 years old! To put that into perspective, the USA became an independent nation just 241 years ago.
Although we can’t be certain exactly how old the shark is, because carbon-dating doesn’t produce exact dates, she could be anywhere between 272 and 512 years old!
You probably already know that you’re more likely to get struck by a coconut than be bitten by a shark, but did you know that you’re also more likely to be bitten by another person? If you want to get really specific, football players have a higher chance of being bitten by Luis Suarez (1/2,000) than you do of being bitten by a shark (1/3,700,000).
Each year in New York City, there are 10 times more human-on-human bites than there are shark-on-human bites worldwide.
Although it’s a common misconception that all sharks need to keep swimming in order to breathe, some species will indeed die from lack of oxygen if they stop moving. Species including great whites, makos, and whale sharks need to constantly keep moving due to the type of ventilation system that they use to breathe.
All sharks breathe using their gills, but species that are not active swimmers use a type of breathing that requires them to draw water into their mouths (which they can do without moving), rather than ventilating their gills by swimming quickly.
Most people seem to be more fascinated by what sharks eat than they are about how much sharks eat, but it’s important to note that they can get through a surprising amount of food each year. The most impressive diet belongs to great white sharks, because they can process 11 tonnes of food each year! In comparison, the average person eats about half a tonne of food per year. That being said, a lot of sharks will only eat when they’re hungry – that’s why you won’t see them feeding on the rest of our fishy friends at the aquarium!
All fish have skeletons made up of either bone or cartilage. Despite their size, sharks fall under the cartilaginous fish category, which is why it is so rare to find complete shark fossils – because cartilage doesn’t preserve as well as bone.
Cartilage does, however, have an advantage over bone: it has roughly half the density, helping to significantly reduce a shark’s overall weight.
When you think of sharks, you probably have something large and menacing in mind, but they actually come in a variety of shapes and sizes. In fact, the smalleye pygmy shark is small enough to fit in your hand! These tiny sharks are known to grow to only 8.7 inches in length.
We have sharks of all different sizes – our zebra sharks can reach a whopping 3 metres and blacktip reef sharks can grow up to two metres (the same size as a large Christmas tree), whilst our crested horn sharks are no more than 1.2 metres.
Although sharks come in all shapes and sizes, what most species have in common is that they would surely sink under their own weight if it wasn’t for the in-built floatation devices they have. Like all cartilaginous fish, sharks use their oily livers to help them stay buoyant. A shark’s liver can make up 30% of its total bodyweight, and thanks to oil being lighter than water, it stops the shark from sinking.
Sharks have an extra sense called electroreception, which means that they can detect electrical currents. Given that all living things emit electric currents, this sixth sense helps sharks to expertly hunt their prey.
The sources of their electroreception are small pores around their faces, and they are filled with electrically conductive jelly.
Biofluorescence is common in many marine creatures that dwell in the dark depths of the ocean, so it comes as no surprise that sharks can glow in the dark too. Swell sharks are not well-known, because they tend to live 1,640ft below the surface, but scientists have recently monitored these shy species and have found that their skin turns a glowing green colour in the moonlight.
Sharks may have a reputation as fierce predators, but every so often, something else takes a chunk out of them, rather than the other way around. Thankfully, sharks are capable of healing themselves incredibly quickly, and even large wounds don’t seem to faze them.
Injuries that would surely be fatal, or at least require medical intervention in other animals, can seem to heal in shark species in a matter of months.
Now that you’ve brushed up on some lesser-known shark facts, come and get up-close and personal with our sharks and grab a front-row seat to one of our shark talks and feeds. Make the most of our seasonal discounts by booking your tickets online.