It has perhaps the most confusing name of
any shark, and a mouthful of razor-sharp,
pointy teeth!
I'm Jonathan Bird, and this is Shark Academy!
It's known by many names: the Spotted Ragged
Tooth shark, the Gray Nurse Shark, the Sand
Tiger shark...but it's not a Sand Shark, it's
not a Tiger shark, it's not a Nurse shark.
It's a Sand Tiger Shark.
Very confusing.
In spite of the fact that it's called a Sand
Tiger shark, it's not related to the Tiger
shark at all...actually, it much more closely
related to the White shark.
The Great White Shark!!!
When you see a Sand Tiger shark up close,
you'll probably notice there's a mouth full
of very intimidating-looking teeth.
They're long, they're skinny, and they're
pointy.
These are teeth that are designed for catching
small, slippery fish.
They're not teeth designed for taking big
bites.
They're designed for just catching things
and letting them not get away, so their teeth
kind of act like the barb on a fish hook.
So even though they look really aggressive,
they're actually not the type of shark that
typically would bite a human.
So, because this shark looks really mean—but
it's actually not mean at all—it's one of
the most popular sharks for captivity in aquaria.
It's one of the sharks you are most likely
to see if you visit someplace like the New
England Aquarium, or the Georgia Aquarium,
or the Mystic Aquarium.
As you know, sharks don't have swim bladders
so they tend to sink.
Most sharks just have to deal with it by swimming
along and using their pectoral fins to keep
them up off the bottom.
But the Sand Tiger has evolved a very clever
way of dealing with that.
They go to the surface and they gulp air into
their stomachs—so they treat their stomach
almost like a swim bladder.
The Sand Tiger shark is perhaps most famous
for being one of the species of sharks that
undergoes a reproductive practice known as
Intrauterine Cannibalism.
The female has a pair of uteruses, and each
uterus starts out with about fifty baby Sand
Tiger sharks in it, but guess what?
The first one that reaches about four inches
long eats all of his or her siblings!
That's the cannibalism part.
So, twelve months later, after the gestation
is over and the baby sharks are born, out
of fifty sharks in each uterus (that's a hundred
sharks!) only TWO are born!
That is weird!
For some reason that nobody can explain, Sand
Tiger sharks love to get together (what scientists
call "aggregate") in various places around
the world.
There are places off North Carolina in the
United States, places off South Africa, and
places off Australia where the sharks just
seem to gather at certain times of the year.
And people think they are mating or something,
but nobody has ever been able to figure out
exactly what they are doing.
They like to get together for human week.
If you want to learn more about Sand Tiger
sharks, we did a big expedition to try to
figure out what they were doing on the wrecks
off North Carolina.
Click the link below and watch the adventure!
Until next time, I'm Jonathan Bird and this
is Shark Academy!
