It was Shark Week last week, and did you know that 80
percent of people who get attacked by sharks survive? So, if you’re terrified
of sharks like my friend, Sharky-Sharky No-Legs, rest easy.
Sharks are fascinating, which is of course why they have
their own week. I also did whales last week, so sharks kind of go along with
that theme, in that both are sea creatures.
The first sharks are believed to have appeared as long as 420 million
years ago, making them literally older than God. Modern sharks began to
appear around 100 million years ago. One of the oldest sharks is the Cladoselache, which
dates from about 370 million years ago:
I was going to make a joke about how funny it looks, but
then I remembered that sharks are still kind of weird-looking.
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| "Stop, you'll make me cry." Image credit: Hermanus Backpackers |
One of the biggest
predators that ever lived was the
Megalodon, a shark that lived from 28 to 1.5 million years ago and is now
extinct.
The Megalodon grew to sizes ranging from 46 to 59 feet (14
to 18 meters). Regular readers will remember that it was the Megalodon’s giant,
fossilized teeth that protected
many Europeans from poisoning throughout the Middle Ages – or so they
believed. Shockingly, dipping a shark’s tooth – even one that is the size of a
toddler’s head – into your poisoned wine will not make it safe to drink.
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| But I can see why they would think that. |
Sharks are cartilaginous fish, like
rays and skates. Their skeletons are made of cartilage. The reason there
are so many fossilized shark teeth floating about is because they are made of
calcium phosphate, which fossilizes easily. Also, a shark may lose more than 30,000 teeth in
its life, replacing them at a rate of once every eight days in some species.
Most shark species grow multiple rows of replacement teeth
on the inside of their jaws, which move forward as if on a conveyor belt. The
exception is the cookiecutter shark, which replaces entire rows of teeth at a
time. It feeds by biting round chunks out of its prey, and has been known to
attack whales, dolphins, porpoises, other sharks, and submarines, which it
finds to be an acquired taste.
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| It also looks like a swimming penis. |
Because a shark has no rib cage, it
can be crushed under its own weight if brought onto land.
Most sharks can’t live in fresh water, although there are at
least two species – the bull shark and the river shark – which can. The bull
shark is one of the
most dangerous species known to man, along with the great white, the
oceanic whitetip and the tiger shark, because they are most often found in
shallow waters where humans are wont to play around looking like seals.
In fact, a couple of years ago, a fisherman named Willy Dean
caught
an 8 foot, 1 inch (2.5 meter) bull shark in the waters of the Potomac
River, at Cornfield Harbor. Just two days earlier, Dean’s friend Thomas Crowder
captured an even bigger, 8 foot, 3 inch (2.51 meter) shark a little upstream,
at Tall Timbers. Though Crowder’s shark drowned and he discarded its corpse,
Dean elected to keep his.
“Some people say shark is good to eat. We’ll see,” he told
journalists.
