Whip It!
Thresher Sharks are a genus marked by their extremely long, beautiful tails. In many cases, their tail is as long as the rest of their body. There are three species of Thresher Shark. They are the Common, Pelagic, and Bigeye.
Above we have a common thresher shark breaching. Threshers are one of the only species of shark known to leap out of the water, or breach, like this. We don't know exactly why they do it, maybe it's fun! Common threshers are the largest getting to be 20ft long! You can tell this one is a common thresher because they don't have "sleeves" connecting the dark coloration on their back to the dark coloration on their fins.
Thresher sharks can use their massive tails to quite easily launch themselves far out of the water. They can swim at 30mph and reach highs of 20ft above the water's surface. With such great heights, how low can they go?
Above is a Bigeye Thresher. They're the medium sized thresher maxing out at 16ft. They have these very prominent grooves on their heads. To me it looks like they're wearing a shark costume. They spend the whole day deep in the twilight zone with very little light filtering in from above. As a result, they have large keyhole shaped eye sockets that let them point their eyes up. They participate in the Diel Vertical Migration, which means every night they come up to the surface to hunt. They aren't warm blooded like us, but they do keep some of their blood warm. Around their brain and their eyes they have a system of blood vessels called rete mirabile. The rete mirabile passes cold blood closely to warm blood from their core so keep their brain and their eyes at a constant temperature as they migrate. We do this all over our own bodies naturally, but they focus on the important stuff.
And this concerned cutiepie is the pelagic thresher, the smallest of the genus maxing out at about 10ft. Threshers keep their mouth open because they are obligate ram ventilators. They have to keep swimming to keep water flowing through their mouths and over their gills. It just so happens that it makes these sharks look like they have a question they're scared to ask. I'll ask it! Why are we here and what's with the tails? Check it out!
The tail is a whip! Thresher sharks rush schools of fish and squads of squids, turn their large fins downwards to brake, and launch their tails over their heads to attack! The end of the tail moves so fast that the water in front of it drops in pressure and boils, forming bubbles that then collapse. This is called cavitation and it makes a shock wave strong enough to stun, kill, or even rupture several fish. As the rest of the school swims away, the shark slowly collects its prize and prepares to do it again.
The tip of their tail can reach 80mph! Instead of trying to choose which tiny fish they're going to pursue at any given moment, they can lash out at the group and get multiple. We don't see a lot of natural weapons in sharks and we certainly don't see any other sharks that can bend their tail over their head like this either.
As a result, they don't need a large mouth or head. Even their teeth are small! They're so streamlined, they remind me of airplanes.
There's so many dimensions to thresher sharks. Their very long, elegant tails are also a fearsome weapon. Their big eyes are cute but they also allow them to hunt and aim in the dark. Their silly face reads as panic but they're actually very capable and sucessful hunters. Definitely not the broad, meaty shark we've come to expect. I'd love to see a 10ft ribbon flutter through the water on a dive! I'd be haunted knowing that meant I was swimming with a 20ft shark! Excellent and Creative!