Top ten Weird Animal Sex Habits in the world

Animals have sex. And as diverse as the animal kingdom is, their sexual habits are bound to reflect just how different they truly are from one another. You have to imagine a furry mammal with opposable thumbs would reproduce by a means vastly different from an ungrippable cephalopod. And what one might call a “pleasure of the the flesh,” another might literally call a pain in the neck. Here are ten of the weirdest sexual behaviors–at least according to us humans anyway–that can be found right here in the animal kingdom.

10:Bonobo

Man may truly have its closest common ancestor in this ape, as it thinks of nothing but sex. After all, everything it does is draped in a hyper-sexual overcoat: they use sex to greet each other, resolve conflict (i.e make-up sex), and as bargaining chips to trade for food. They engage sexually in many of the ways us humans do (e.g. mutual masturbation, oral sex, French kissing) and some we do not (sometimes they fence with their penises, like phallic swashbucklers). And as a result of this sexually-saturated kind of culture, they are an incredibly peaceful species, although they may enjoy the occasional cock spar.

9:Frigatebird

This bird is a romantic at heart. And throat. Just take a look at their mating call: they inflate their throats into a bright red, heart-shaped balloon, like some kind of self-contained Hallmark greeting. Meanwhile, the female seeks out the biggest and brightest balloon, the owner of which earns her. And then while the two go at it, the male will shield her eyes with his wings so she won’t be tempted to run off with some better balloon-owner. This sort of jealousy and and competitiveness is incredibly human-like, only instead of balloons, it’s expensive cars, spiky hair and spray-tans.

8:Honey Bee

Sex is not pleasant for the honey bee. In fact, it is a veritable Kamikaze mission; when the virgin queen bee is sexually mature (after having been fed a kind of nutritious goo by her servants) she will hand-pick a dozen or so bees from the hundreds to serve as her suitor. And here’s where it gets unpleasant: while mating, the male’s genitals will explode inside of her, securing his paternity, himself literally lodged inside of her, as he is effectively killed in the process. The term “getting lucky” holds no meaning here.

7:Straw Itch Mite

These miniature arachnids are sexual barbarians, ultimately depraved beings. At least they would be if they were human. As they are, their iniquities are too microscopic to be consequential; after the males are born–and after they’ve stung and sucked the bodily fluids out of their mothers–they are already sexually mature… and DTF. Anything they see basically (which includes their newborn sisters). Mites have no concept of incest, but if they were human, [insert joke about the Southern U.S. here].

6:Pandas

Panda porn exists. And it is often seminal to a panda couple’s sex life, and their species as a whole. As pandas are endangered, their procreation in captivity is essential for their species to repopulate. And as they often show little interest in sex without any kind of prior stimulation, panda porn was necessarily implemented in a research facility in China, which has shown great success. Which begs the question: are there also panda pizza boys and repairmen?

5:Hyena

A male hyena having sex with a female hyena is a bit like putting a gun in a perfectly-formed holster; the females are equipped with a sort of “anti-penis” that can erect at will–which is actually just an enlarged clitoris. The task of the male is then to sort of occupy this outer-penis. And then out of this penis, the female eventually gives birth. Ouch! Weird! Gross! But true.

4:Red-Sided Garter Snake

These snakes have what Italian Prime Minister Silvio Berlusconi would call “Bunga Bunga Parties.” They indeed involve a disproportionate number of males literally piling upon a single female in a pheromone-soaked snake pit. The pheromones released by the female snake are actually what draw the snakes, each armed with a dual-penis which clamors to secure the female. More curious still, there are transgender snakes who also release pheromones, claiming a pile of snakes for themselves. This is attributed to a possible desire for body heat and protection.

3:Dolphin

The male dolphin is one randy bastard. It’ll essentially hump-back anything it can get its fins on, including inanimate objects and sea turtles. Furthermore, the dolphin’s swivelly penis is actually capable of gripping things, making it a sort of exploratory apparatus. It can be said, then, with absolute certainty that a dolphin is truly guided by its penis. Although, they make terrible lovers (it only takes 12 seconds for them to release).

2:Clownfish

The clownfish can switch genders readily. And that is without invasive surgery; here’s why: there are three ranks of clownfish, ranked according to size from largest to smallest–the female, the breeding male, and the non-breeding male. When the female dies or is captured, the breeding male up and switches sex, as the non-breeding males are promoted to the rank of breeding male. So perhaps we can assume the clownfish is named such because, like a clown, it too sometimes wears the makeup in the relationship.

1:Snail

Do not get on a snail’s bad side (or its good side for that matter), it is armed and dangerous. The weapon: a sharp-tipped sperm dart (which is deployed from the backs of their eyes, where they keep their genitals). Snails are in fact hermaphrodites who don’t auto-impregnate. Instead they seek a sexual partner–also armed with this sort of dart-gun–and engage in dangerous eye sex as if it were some sort of shoot-out, dodging bullets and also seeking to fill the other’s uterus with a calcified, mucous-covered spike. For those who find the missionary position underwhelming, at least there’s no risk of losing an eye in the process.

Source:http://listverse.com

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How many species have been identified on earth?

How many species are there in the world?

Answer by Liz Osborn (© Current Results Nexus): 
Scientists have described over 1.7 million of the world's species of animals, plants and algae, as of 2010.
The list below gives the number of species known in the world for each major category of animals and plants.
The numbers most accurately represent all living species of mammals, birds and coniferous plants. Only for those groups have scientists almost completely identified all the world's species.
Biologists have yet to describe many species of plants, invertebrate animals and lichens. So the number of these species known to science increases substantially every year.
The greatest species diversity exists among insects, which account for one million of the earth's species known to science. Mammals make up one of the smallest groups, with just 5,490 members.
Altogether the earth's oceans, lakes, continents and islands support over 62,000 identified species of vertebrate animals and 320,000 species of plants.

How many species are known to currently exist in the world.

Category	Species	Totals
Vertebrate Animals
Mammals	5,490
Birds	9,998
Reptiles	9,084
Amphibians	6,433
Fishes	31,300
Total Vertebrates		62,305
Invertebrate Animals
Insects	1,000,000
Spiders and scorpions	102,248
Molluscs	85,000
Crustaceans	47,000
Corals	2,175
Others	68,827
Total Invertebrates		1,305,250
Plants
Flowering plants (angiosperms)	281,821
Conifers (gymnosperms)	1,021
Ferns and horsetails	12,000
Mosses	16,236
Red and green algae	10,134
Total Plants		321,212
Others
Lichens	17,000
Mushrooms	31,496
Brown algae	3,067
Total Others		51,563
TOTAL SPECIES		1,740,330

The species totals do not include domestic animals such as sheep, goats and camels. Nor do they include single-celled organisms such as bacteria.

Reference

The World Conservation Union. 2010. IUCN Red List of Threatened Species. Summary Statistics for Globally Threatened Species. Table 1: Numbers of threatened species by major groups of organisms (1996–2010)

Source: http://www.currentresults.com/
Answer by explorebiodiversity.com: 
This is a very good question, but the truth is, its very hard to know, or even estimate. Currently there are about 1.4 million species described. Yet, we're probably far from being close to the actual number of species.

Take this into consideration. In a famous study conducted in Panama, 19 trees were "fogged" with insecticide and the dead were collected as they fell through the canopy. In this study, nearly 1,200 species of beetles alone were collected. Of those, 80 percent were not known to science. While it may be dangerous to extrapolate numbers like these to other places, it gives at least a high estimate of the number of species that could exist on earth - that high estimate being around 100 million species. A low estimate is 2 million. The best estimate might be around 10 million. But even if that’s the case, it means we've only known about a small fraction of what is presently there.

Many of the species that we're discovering live in areas that are not often studied. Take the sea floor for instance. Hydrothermal vents along the floor provide a type of chemical energy for bacteria. These bacteria use this energy like plants use the energy of the sun. They then form the base of a giant food web thousands of feet below the surface. Only until recently have we been able to discover this new habitat. Now scientists believe there could be as many as a million species just in on the ocean floor.

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Why do fireflies light up?

 Why do fireflies light up?  

Answer1:  Marc Branham, an assistant professor in the department of entomology and nematology at the University of Florida, explains.

Fireflies produce a chemical reaction inside their bodies that allows them to light up. This type of light production is called bioluminescence. The method by which fireflies produce light is perhaps the best known example of bioluminescence. When oxygen combines with calcium, adenosine triphosphate (ATP) and the chemical luciferin in the presence of luciferase, a bioluminescent enzyme, light is produced. Unlike a light bulb, which produces a lot of heat in addition to light, a firefly's light is �cold light,� without a lot of energy being lost as heat. This is necessary because if a firefly's light-producing organ got as hot as a light bulb, the firefly would not survive the experience.

A firefly controls the beginning and end of the chemical reaction, and thus the start and stop of its light emission, by adding oxygen to the other chemicals needed to produce light. This happens in the insect's light organ. When oxygen is available, the light organ lights up, and when it is not available, the light goes out. Insects do not have lungs, but instead transport oxygen from outside the body to the interior cells within through a complex series of successively smaller tubes known as tracheoles. For a long time it was a mystery as to how some firefly species manage such a high flash rate, considering the relatively slow speed of the muscles that control oxygen transport. Researchers fairly recently learned that nitric oxide gas (the same gas that is produced by taking the drug Viagra) plays a critical role in firefly flash control. In short, when the firefly light is �off," no nitric oxide is being produced. In this situation, oxygen that enters the light organ is bound to the surface of the cell's energy-producing organelles, called the mitrochondria, and is thereby not available for transport further within the light organ. The presence of nitric oxide, which binds to the mitochondria, allows oxygen to flow into the light organ where it combines with the other chemicals needed to produce the bioluminescent reaction. Because nitric oxide breaks down very quickly, as soon as the chemical is no longer being produced, the oxygen molecules are again trapped by the mitochondria and are not available for the production of light.

Fireflies appear to light up for a variety of reasons. The larvae produce short glows and are primarily active at night, even though many species are subterranean or semi-aquatic. Fireflies produce defensive steroids in their bodies that make them unpalatable to predators. Larvae use their glows as warning displays to communicate their distastefulness. As adults, many fireflies have flash patterns unique to their species and use them to identify other members of their species as well as to discriminate between members of the opposite sex. Several studies have shown that female fireflies choose mates depending upon specific male flash pattern characteristics. Higher male flash rates, as well as increased flash intensity, have been shown to be more attractive to females in two different firefly species.

The adult fireflies of some species are not luminous at all, however, and instead use pheromones to locate mates. The use of pheromones as sexual signals appears to be the ancestral condition in fireflies with the use of luminous sexual signals as being a more recent development. There are species that employ both pheromonal and luminous components in their mating systems. These species appear to be evolutionarily intermediate between the pheromone-only fireflies and flash-only fireflies.
Source:http://www.scientificamerican.com/


Answer2: Fireflies or lightning bugs make light within their bodies. This process is called bioluminescence and is shared by many other organisms, mostly sea-living or marine organisms. Fireflies light up to attract a mate. To do this, the fireflies contain specialized cells in their abdomen that make light.

The cells contain a chemical called luciferin and make an enzyme called luciferase. To make light, the luciferin combines with oxygen to form an inactive molecule called oxyluciferin. The luciferase speeds up the reaction, which occurs in two steps:

The luciferin combines with adenosine triphosphate (ATP), which is found in all cells, to form luciferyl adenylate and pyrophosphate (PPi) on the surface of the luciferase enzyme. The luciferyl adenylate remains bound to the enzyme:
luciferin + ATP -------------> luciferyl adenylate + PPi
The luciferyl adenylate combines with oxygen to form oxyluciferin and adenosine monophosphate (AMP). Light is given off and the oxyluciferin and AMP are released from the enzyme's surface:
luciferyl adenylate + O2 -------------> oxyluciferin +AMP + light
The wavelength of light given off is between 510 and 670 nanometers (pale yellow to reddish green color). The cells that make the light also have uric acid crystals in them that help to reflect the light away from the abdomen. Finally, the oxygen is supplied to the cells through a tube in the abdomen called the abdominal trachea. It is not known whether the on-off switching of the light is controlled by nerve cells or the oxygen supply.

The luciferin-luciferase chemical reaction has been used for years to measure the amount of ATP produced in cells and by various chemical reactions. Recently, the gene (section of DNA coding for the protein) for the luciferase enzyme has been isolated, placed in the genes of other organisms, and used to follow the synthesis and/or expression of other genes (i.e. used as a reporter gene).
Source:http://animals.howstuffworks.com/

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Why Is Snow White?

Why is snow white if water is clear?

Answer By Rachelle Oblack( About.com Guide) :Most of us recognize that water, in pure form, is colorless. With impurities, such as in a muddy river, water takes on multiple other hues.
Even snow can take on other hues as well depending on certain conditions. For instance, the color of snow, when compacted, can take on a blue hue. This is common in the blue ice of glaciers.
Let's go back for a moment and discuss the properties of snow and ice. Snow is tiny ice crystals accumulated and stuck together. If you were to look at an ice crystal by itself, you would see that the ice crystal is also clear. But snow is different. When snow forms, hundreds of tiny ice crystals accumulate together to form the snowflakes we are familiar with.
Some people have even asked what the record for the largest snowflake. But this is hard to quantify considering snowflakes as we commonly call them are more of a bundle of individual snowflakes. A layer of snow on the ground is also mostly air space. Lots of air fills in the spaces between snowflakes.

The Properties of Light and Snow

The reason we see snow in the first place is due to light. As snow falls through the atmosphere and lands on the ground, light is reflected off the surface of the ice crystals. Since the snow has multiple facets, some of the light is scattered.
Visible light from the sun is made up of a series of wavelengths of light on the electromagnetic spectrum that our eyes interpret as different colors. When light hits an object, different wavelengths of light are absorbed and some are reflected back to our eyes. To complicate matters, light passing through ice will not continue through the ice crystal without first changing directions or reflecting off an interior angle within the ice crystal.

No one really ever sees one snowflake at a time. Most of the time, we see huge collections of millions of snowflakes on the ground. As light hits the snow on the ground, there are so many locations for light to be reflected, that no single wavelength of light gets absorbed or reflected with any consistency. Most all of the white light from the sun hitting the snow will reflect back and still be white light. Therefore, snow on the ground appears white.

One other important point to remember is that snow is indeed tiny ice crystals. Ice itself is not transparent like the glass in a window, but translucent. Light does not pass through ice easily. Instead, it bounces around back and forth within the ice crystals. As the light inside an ice crystal bounces around off the interior surfaces, some light is reflected and other light is absorbed. With the millions of ice crystals in a layer of snow, all this bouncing, reflecting, and absorbing leads to a neutral ground. That means there is no preference to one side of the visible spectrum (red) or the other side (violet) to be absorbed or reflected. The sum total of all that bouncing leads to white.

The Color of Glaciers

Glacial ice will often take on a blue color. Remember, an accumulation of snow has a lot of air separating the snowflakes. Glaciers are different. Glacial ice is not the same as snow. Snowflakes accumulate and get packed together to form a solid and mobile layer of ice. Much of the air that was separating snowflakes is now squeezed out of the ice layer.
As light enters a deep layer of ice, the light gets bent causing more and more of the red end of the spectrum to be absorbed. As more red wavelengths are absorbed, more blue wavelengths are available to reflect back to your eyes. The color of glacier ice will then appear blue.

The Varied Colors of Snow

With blue and white snow or ice, many people wonder if snow can take on other colors. In some instances, impurities in snow are what cause it to appear a different color. For instance, algae can grow on snow making it appear more red, orange, or green. Dirt and debris near a road can make snow appear gray or black.
Snow Lesson Plans

A wonderful lesson plan on snow and light is found in the Physics Central library. With only minimal preparation, anyone can complete this experiment on snow. The experiment was modeled after one completed by Benjamin Franklin.
Source:http://weather.about.com/

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Why can't animals talk like humans?

Why can't animals talk like humans?
Answer by ZOMBIE55:
Here's a scientific question to you all: Why is it that animals (well apart from parrots and maybe some other minor exceptions) cannot speak like humans can?

Why can't animals also understand what we are saying to them?

Also, do you know, why can't human beings understand the language of animals? I've read a lot of speculations that say that we human beings still lack the necessary intelligence to "understand" the simpler means of communication of non-human animals, but is that really the case? And do we humans need to be criticized for it?

And do you know, why is it that when people say that human beings do not understand the "language" of animals, it is like people say from France do not understand Spanish?? When in reality, ANY human being can learn a foreign (human) language when they study enough to do so (after all, I come from Russia and before I moved to UK, I hardly knew a word of English, but I have learned it and I can speak it now) but cannot tell what elephant says when it rumbles for instance?

Also, not to devour animals in any way or accuse them of lacking intelligence, but does anyone seriously think that animals communicate in ways even remotely similar to humans? I mean, I'm pretty sure than unlike human beings, animals don't talk about things like politics or contemplate about the universe, Jesus Christ or what kind of music they like among other things. They don't go on internet discussing value of Britney Spears and how she affects the modern society, nor do they talk about how great The Beatles or The Rolling Stones are. I'm pretty sure for most of them, their "dialogue" is limited to stuff like "Food", "leave me alone", "there's danger over there" and "sleep time".

(Though seriously, if they could speak like us, and their brains were also a bit more developed to convey the thoughts and philosophise, they may even be able to save themselves from humans' bad deeds towards them like cruelty and butchering, whether for the good of us or otherwise.)

So anyways, apart from parrots and maybe other minor exceptions, why can't the majority of animals talk like humans can?
Source:http://rateyourmusic.com/
Can animals talk, and what do they say? 
Plenty of them can – although not exactly the way we do. We still can’t understand most of them, or what they’re saying, but a lot of it seems to be about food, fighting and lurrrrrve.

Can’t some of them talk we do, like parrots? I even saw a cat say ‘hello’ once on the Internet...
Animals don’t have the same equipment as we do for talking. Many have tongues, of course – but tongues are just for shaping the sounds of words that start as vibrations in our throats. Most animals lack complex vocal cords like we have in our throats, so they can’t make smooth vowel sounds. Parrots and a few other animals can make noises that sound like words, but they’re really just mimicking us, and they don’t really understand what they’re saying.


How do they talk, then?
Lots of animals can ‘talk’ by making noises that they can understand, even if we can’t. Birds do this when they chirp and sing, cats when they meow and purr, and dolphins when they click and whistle. Many of these noises translate to simple phrases like ‘I’m hungry’, ‘I’m angry’, ‘feed me’ and ‘leave me alone’. But some may be quite complex: dolphins chatter to each other constantly as they play, and seem to give each other instructions when they hunt fish together in groups.

Other animals use signals and sign language to talk to each other. Bees do a complicated dance to tell other bees in which direction to go to find food. To us, it just looks like a figure of eight with a bum-waggle in the middle. But, if the bee ‘draws’ the eight upright, it means ‘head towards the Sun’; if it draws it at an angle, that tells the other bees what angle from the Sun they should head away from the hive at. (So, for example, an eight on its side would mean ‘head off at 90° to the sun’). A gorilla leading a troop through the forest will do a similar thing – by thumping two trees, one after the other. The line between the two trees tells the other gorillas which way they’re headed for the day, and they all understand at once.

Not bad. But that’s not real sign language is it? It’s still just giving directions. What about words and sentences?
Scientists have managed to teach a few chimpanzees some basic, human-style, sign language. But they can only do a few words, and don’t seem good at putting sentences together. It may be that only humans have evolved the bits of brain that deal with making and understanding whole sentences.

Or it could be that animal sentences just look different.

How d’you mean?
Well dolphins and whales have pretty complex brains, too, and we still don’t understand what all their clicks and whistles mean, so they could be talking in full sentences for all we know. Some types of octopus and squid might even be able to do it. Some cuttlefish can hold ‘conversations’ with up to four friends at once, by using different sides of their bodies to make patterns of light and colour 21 – patterns that change so fast we can hardly see them. Could be a lot going on there.

Will we ever be able to understand them?
Maybe, one day. It’s possible that, in the future, we’ll have computers so powerful that they’ll be able to decode the dolphin clicks – even translate Cuttlefish into English.

Crazy. I wonder what they’ll say?
Maybe something like: ‘Do you mind? I wasn’t talking to you...’
(http://www.sciencemuseum.org.uk/)

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Why Do Animals' Eyes Glow In The Dark?

Why Do Animals' Eyes Glow In The Dark?
Answer by ANDREA SEABROOK:  Eyes that glow in the pitch-black night make for many a scary tale. But why do some animals' eyes glow at night?

"A lot of the animals we see, especially the ones that go out at night, have a special, reflective surface right behind their retinas," says Dr. Cynthia Powell, a veterinary ophthalmologist at Colorado State University. That light-reflecting surface, called the tapetum lucidum, helps animals see better in the dark.

When light enters the eye, it's supposed to hit a photoreceptor that transmits the information to the brain, Powell explains. But sometimes the light doesn't hit the photoreceptor, so the tapetum lucidum acts as a mirror to bounce it back for a second chance.

A large number of animals have the tapetum lucidum, including deer, dogs, cats, cattle, horses and ferrets. Humans don't, and neither do some other primates. Squirrels, kangaroos and pigs don't have the tapeta, either.

And not all eyes animals' glow the same color. Powell says this is due to different substances — like riboflavin or zinc — in an animal's tapetum. "Also," she says, "there are varying amounts of pigment within the retina, and that can affect the color." Age and other factors also can change the color, so even two dogs of the same species could have eyes that glow different colors.

Cats often have eyes that glow bright green, though Siamese cats' eyes often glow bright yellow. Cat tapeta also tend to reflect a little bit more than dogs, Powell says.

"One of my favorites are miniature schnauzers," she says, which have eyes that tend to glow turquoise. "It's really beautiful."
Source:http://www.npr.org/ 
Answer by Orlin Sorensen  :
If you've ever wondered why your cat's eyes seem to glow in the dark, or pondered how a hummingbird finds its way to certain nectar-filled flowers, what you are really asking is, do animals see the way we do? Though we might like to think that animals see the world with the same colors and shadows as human beings-although maybe from a different angle, perhaps high in the sky like an eagle, or under the sea like a shark-the truth is that animal vision is not like our own and differs greatly among animal species.

Glow in the Dark

Human beings are not like tigers, or housecats for that matter, whose eyes are superbly well adapted to seeing in the dark. One reason is that cats have more rods than cones in their retinas, unlike humans, making kitty's night and motion vision superior. (Rods are the receptors that the eye uses for nighttime viewing and sudden movement; cones are used during the daytime and process color information.)

Also, cats' pupils are shaped differently than those of humans (they are elliptical rather than round), which allows for a much larger pupil size. In fact, the most notable feature of nocturnal animals is the size of their eyes. The reason for this is that large eyes can collect more ambient light.

Fun fact: An owl's eyes fill over half of its skull!

As well, cats' eyes open and close much faster than do ours. And cats have a special membrane on the back of their eyes (called the tapetum lucidum, literally meaning "bright carpet") that increases the quantity of light caught by the retina. The tapetum collects and re-emits light back to the retina, giving the rods a second chance to absorb the image, thus maximizing their sensitivity to low light levels. As this light is reflected off the tapetum, the animal's eyes appear to glow.

And You Thought "Four-Eyes" Was Insulting

How about "hundred eyes"? That's the insult you'd have to hurl at a scallop. The scallop's mantle is lined with small blue eyes. Each eye has a lens and a retina which is attached to a branch of the optic nerve. Behind the retina is a tapetum, perhaps the only thing a cat and a sea creature have in common! The hundred or so eyes work together to alert the mollusk to changes in light and motion.

One Step Beyond

When it comes to light, we humans are limited. The light we see with our eyes is really a very small portion of the electromagnetic spectrum.

Bees and butterflies may be small, but they can see better than us. In fact, their range of vision extends into the ultraviolet part of the spectrum, which is invisible to us with the naked eye. The leaves of the flowers they pollinate have special ultraviolet patterns which guide the insects deep into the flower to locate the plant's nectar. So, next time you admire a pretty flower, just think about all the beauty you're not seeing!

Some snakes have an extra pair of "eyes," or sensory organs, located on their foreheads that can detect infrared radiation. They can "see" the heat of a mouse from a meter away, even in conditions where our eyes would detect only pitch black.

Even those common urban pests, pigeons, have one up on us: Pigeons can see patterns of polarized light in the daytime sky which are invisible to us, providing yet another clue to the remarkable homing abilities of these birds.

Don't Judge a Creature by Its Cones

We couldn't forget to tell you about shark vision. Sharks do not possess the same variety of photoreceptors as humans. They have few retinal cones, and as a result, for years it was thought that their vision was much less acute than ours. However, though different from our eyes, shark eyes work just as well, relying on visual pigments such as rhodopsin to supply the color vision we achieve with cones.

Of course, sharks have other advantages as well: They have a sharp sense of hearing and can hear prey many miles away. They also possess a superior sense of smell and can smell even the smallest drop of blood over long distances. Once they are close to their prey, they employ special sensory pores on their heads to detect electrical fields created by prey. Getting scared yet?

Before you go out and rent Jaws, know that you are much more likely to get hit by lightning than eaten by a shark. And here's another cool shark fact: Like cats and scallops, sharks, too, have a tapetum, which gives them about 10 times the light sensitivity we have. This works well in the dark, but the light-enhancing mechanism can be a bother during daylight. So sharks have evolved a fun solution: Many species of sharks have migratory pigment cells that can close up the tapetum under bright-light conditions-basically, a pair of built-in shades!
Source:http://chetday.com/

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