Posted : August 2013
Author : Matt Weber
10 Sleeplessness
Everything needs sleep. The human world record holder, Randy
Gardner, stayed awake for 11 days straight. By the fourth day, he was
hallucinating. Not sleeping will eventually kill you and every other mortal
creature with higher brain functions - except dolphins, which have apparently
found a way around sleep. Baby dolphins actually forgo sleep for the first
month of life - and so, therefore, do their parents.
The trick is that these amazing sea critters can shut half of their brain off
at a time. Scientists tested dolphin reactions without rest for five days
straight and their reaction time never slowed. Blood tests for signs of stress
or sleep deprivation turned up negative. Dolphins may be able to do this
indefinitely. Another study showed that dolphins can use their sonar for 15 days straight
with almost perfect accuracy. It makes sense that dolphins evolved a way to
keep an eye out for predators while they’re dozing in the open ocean. But the
truly fascinating part about all of this is that tests showed visual
information was being passed from the snoozing side to the active side. Even
though they shut down half of their noggin at a time, the other half can take
over all the functions. It’s almost as if they have two brains.
Everyone knows about dolphins and sonar. With those
trademark clicks and squeaks they use sound to perceive the world around them.
You would think that would mean their other faculties would be diminished. But
in fact, they have better eyesight than we do. To start, dolphins have an eye
on each side of their head, which gives them a panoramic visual range of 300
degrees. They can see behind themselves, and each eye can move independently of
the other, meaning they can look two different directions at the same time.
They also have a reflective layer of cells just behind the retina called the
tapetem lucidem. This helps them to see exceptionally well in low light. And as
if all of that wasn’t enough, dolphins can see just as well out of the water as
in it.
8 Skin
Why aren’t dolphins covered in barnacles? Whales are coated
in the things, but the dolphin family seem to be immune. Look at Flipper or Shamu
(killer whales are just big dolphins by the way): They’re clean and glassy
smooth. So what’s their secret? Super skin.
Dolphin’s unique skin gives them all kinds of advantages. To start, while their
epidermis is no tougher than ours, it is about 10 to 20 times thicker than any
land animal. It also grows about nine times faster than ours. An entire layer
of skin is replaced every two hours. This rapid skin regeneration helps to keep
dolphins smooth, silky, and hydrodynamic. Dolphins also have microscopic
ripples in their skin, which help them travel faster through the water and
prevent parasites from grabbing hold. But the real secret of why dolphins are
so clean is that they secrete a special gel, which resists the mucus that
barnacles and their ilk cling on with. So dolphins are covered in some sort of
natural glue solvent. Even if something does find a way to latch on, this
dolphin grease also contains enzymes that attack parasites.
7 Respiration
It turns out that dolphins are pretty good swimmers. The
bottlenose can hold its breath for 12 minutes and dive nearly 550 meters (1800
ft). Part of the reason dolphins can do this is because they’ve got incredible
lungs. Though they aren’t much bigger than our own, they’re much more
efficient. With each breath, a dolphin exchanges 80 percent or more of its lung
air. We puny humans can only get out about 17 percent. Their blood and muscles
can store and transport more of that oxygen, too. This is because they have
more red blood cells, which in turn have greater concentrations of hemoglobin
than we do.
But this still doesn’t fully explain how dolphins can hold their breath for so
long and dive so deep. To accomplish this feat, they can also restrict where
their blood circulates. During long dives, blood is shunted away from the
extremities and sent to the heart and brain. All nonessential tissues are cut
off and forced to rely on their own internal supplies.
6 Healing
Dolphin healing is pretty much impossible. Seriously,
scientific opinion can be summed up as “its healing is almost alien compared to
what we are capable of.” They’ve been known to survive wounds the size of
basketballs, and they will regrow that huge chunk of flesh in a couple of
weeks, actually returning to the original contours instead of leaving a gaping
scar. They don’t just heal, they regenerate. Their recuperative abilities have
been likened to fetuses in the womb. But besides Wolverine-esque recovery
skills, dolphins don’t bleed out either. Typically, when someone takes a
shovelful of flesh out of your side you’ll hemorrhage to death. However, it’s
believed dolphins use the same mechanics that enable them to dive to great
depths to help them constrict blood vessels to stem the flow.
5 Pain
Dolphins don’t care about little inconveniences like
mind-numbing agony. After receiving crippling injuries that would incapacitate
just about any other creature on Earth, dolphins have been observed playing,
swimming, and feeding normally. They give no outward signs of the gaping wound
full of exposed nerve endings that should be screaming bloody murder. And it’s
not that they don’t feel pricks and pokes. Dolphins are just as sensitive as we
are. But when inflicted with a serious wound they shrug it off. It’s believed
they must be able to produce natural morphine-strength painkillers - that are
nonaddictive.
Try losing a bucket’s worth of flesh then going back to work in the morning
with only your body’s natural painkillers to tide you over and see how that
works out for you. Since predators go after the weak, not showing pain or
distress makes evolutionary sense. If you just got a hole the size of a melon
blown in you, you really don’t want to advertise that fact to any sharks that
might be lurking nearby.
4 Thrust
In 1936, famed British zoologist Sir James Gray was amazed
by how fast dolphins could swim. He’d studied their anatomy extensively and the
best he could guess at was that dolphin skin had to have some sort of magical
anti-drag properties. This was known as “Gray’s paradox,” and it wasn’t officially
solved until 2008.
Gray wasn’t completely wrong - dolphins do have anti-drag properties, but he grossly underestimated the power that a dolphin’s muscles produce. Olympic swimmers can produce about 60 or 70 pounds of thrust in the water. A dolphin moving at average speed hits 200. Swimming at full tilt, these aquatic speed demons can produce 300 to 400 pounds of thrust. That’s over five times what the most physically fit person on earth can do. And dolphins are extremely energy efficient, too. A human can only convert about four percent of their energy into forward momentum in the water. Dolphins, on the other hand, can turn 80 percent of their energy into thrust, making them some of the most efficient swimmers in the ocean.
Gray wasn’t completely wrong - dolphins do have anti-drag properties, but he grossly underestimated the power that a dolphin’s muscles produce. Olympic swimmers can produce about 60 or 70 pounds of thrust in the water. A dolphin moving at average speed hits 200. Swimming at full tilt, these aquatic speed demons can produce 300 to 400 pounds of thrust. That’s over five times what the most physically fit person on earth can do. And dolphins are extremely energy efficient, too. A human can only convert about four percent of their energy into forward momentum in the water. Dolphins, on the other hand, can turn 80 percent of their energy into thrust, making them some of the most efficient swimmers in the ocean.
3 Infection
Dolphins are able to swim with open wounds in the
bacteria-riddled ocean and not die of infection. And the incredibly filthy
teeth of sharks don’t bother them much either. Without hospitalization, humans
would die of sepsis within a few days of a shark bite . But dolphins seem to do
just fine. In fact, they won’t get any infection at all, which has been
described as no less than “miraculous.” And yet dolphins have an immune system
similar to ours, so how have they acquired this super resilience?
Well, no one really knows. The best guess that science has is that dolphins
have managed to siphon off antibiotics made by plankton and algae. Chemicals
produced by these microscopic creatures have been found in dolphin blubber. As
the blubber decomposes at the site of the wound, it gives off these natural
antibacterial substances. How they can store these lifesaving chemicals just
under their skin instead of metabolizing or excreting them is still a mystery.
2 Magnetic Sense
Why do dolphins and whales strand themselves on beaches?
It’s a mystery that has confounded researchers for years. Theories include some
strange disease, pollution, or military sonar testing. But autopsies have not
produced a smoking gun. And when you take into account that strandings have
been recorded for hundreds of years, it probably rules out humans as the cause.
Now, some researchers are beginning to suspect that it’s all the sun’s fault.
Dolphins and whales have magnetite crystals in their brain to help them sense
the magnetic field of the earth. With this built-in GPS, they can navigate the
featureless oceans with ease. One group of researchers plotted stranding spots
along the US East Coast and found that they coincided with places where local
magnetic rock reduces the Earth’s magnetic field. So a deep-sea dolphin or
whale that depends on its magnetic sense might not see the shore till it’s too
late. Other evidence suggests that when the sun throws too much radiation our
way, it also screws up the magnetic senses of aquatic mammals. Researchers at
the University of
Kiel have shown that most
beachings correlate with the portions of the sun’s solar cycle that produce a
higher flux of radiation. This might explain why rescued dolphins and whales
will often turn around and beach themselves again.
1 Electroreception
Dolphin sonar is pretty incredible. The ability to detect
objects from a distance through some sort of aquatic beatboxing is just
amazing. And combined with the other senses we’ve already covered, dolphins
have some of the keenest senses of any animal on the planet. Yet Mother Nature
isn’t done with these sea critters. They can boast one other super sense:
electroreception. Dolphins can actually sense the electrical impulses given off
by all living things. Guiana dolphins live around the coast of South America
and resemble the common bottlenose. Researchers discovered a depression on
their rostrum (snout) that can detect electrical impulses given off by the
muscles of fish. Scientists liken the sensitivity of its electroreception to
that of a platypus. They probably use this ability to search for fish hiding in
the mud. Sonar is great for detecting objects at a distance, but not so much
when you get up close. Scientists suspect that all dolphins and even some
whales may have this ability.
~Blog Admin~
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