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Scalloped Hammerhead Sharks | SHARK ACADEMY

September 11, 2019


It looks mean and it travels in big groups,
but it’s actually a scaredy cat. I’m Jonathan Bird and this is Shark Academy! Hammerheads are very easy to identify because
of that big, hammer-like head. Of course there are multiple species. The Scalloped Hammerhead
has a particular shape that makes it easy to identify, but Scalloped Hammerheads are
often identified because of the fact that they live in large schools. Hundreds of hammerheads! Dude! Scalloped Hammerheads often come to cleaning
stations, where they slow down and hover over the reef, to be cleaned by little fish called
cleaner fish, sometimes butterflyfish, sometimes angelfish, and they pick off little parasites
on their skin. Scalloped Hammerheads like to feed on squid,
way down deep, at night. So when you see them during the day and they’re on the reef,
just swimming around getting cleaned, they’re not feeding. While they have this amazingly aggressive
look, they look like man eaters, right? They are scaredy cats. Scalloped Hammerheads are
afraid of everything. Mostly though, they are afraid of scuba bubbles. So when you are
in a school of hammerheads, if you want to get them close so you can film them, you have
to hold your breath, and be really quiet, and don’t move, and try to, like, hide in
the rocks, and try to be a rock. Because if you move, if you make any bubbles, if you
make any sound, if they see you, if they hear you, they are going to freak out and bolt
in all directions and you won’t see any more hammerheads. They are way more afraid
of us than we are of them. Scalloped Hammerhead sharks have a very high
infant mortality rate, which is to say the babies don’t survive that well. Because
when they are born, it’s like: “Sayonara, see ya later, no college for you, I’m not
going to help you in any way, see ya!” and most of them don’t survive to adulthood.
So, because of that, hammerheads have more pups than the average shark. They’re so
cute! So cute! I like pups! Most sharks, eh, 2 to 4, 6 pups. Scalloped
Hammerheads have dozens of pups, just to deal with the fact that most of them don’t survive
to adulthood. Scalloped Hammerheads tend to have very defined
and repeatable pupping grounds where they pup every single year. For example, Kaneohe
Bay in Hawaii is a well-known Scalloped Hammerhead pupping ground. And there’re almost always
pups to be found there. So there’s a population of sharks that always gives birth to their
pups right in that bay. Most sharks can settle down on the bottom
and breathe by pumping water to ventilate their gills. The hammerhead shark can’t
do that. So Scalloped Hammerheads are swimming all the time…they have to always be swimming
at least a little bit just to keep that water moving through their gills to keep them alive. The hammerhead shark has some of the best
vision in the animal world. Their eyes are way out on the ends of their hammer. Researchers
just recently found out that they can see in stereoscopic vision, which means that they
can see forward with both eyes, just like we can, but also, they can see behind themselves,
above and below. They have the best eyesight of all sharks. I could be wrong. But probably not! Hammerhead sharks have a giant thing that
looks like a wing on their head, and this is no coincidence. It is a wing. It provides
lift. Now a lot of sharks have big giant pectoral fins to do the same thing, but with hammerheads,
they share some of the lift with their head and their fins, so their fins can be smaller.
So between the lift on the head and the lift on the fins, they are very maneuverable. If you ever see a hammerhead when it gets
freaked out, they can turn on a dime, because of the mass of their head and the fact that
they have small pectoral fins. They get some extra lift from that cephalofoil-shaped head.
That was succinct, I think. Well, that’s everything I could fit in on
Scalloped Hammerheads. But if you want to know more, check out the Jonathan Bird’s
Blue World episode on Scalloped Hammerheads linked right down there, and don’t forget
to subscribe to our channel so you can learn everything there is about sharks!

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