10 + 2 Rãs mais Venenosas do Mundo

10 + 2 Most Poisonous Frogs on the World
As children, many of us kept frogs we had found in jars and vivariums, or just took them home to show to our friends. The frogs on this list are a different ball of wax, not creatures anyone in their right mind would want to play with or even touch - in many cases, in fact, they are deadly poisonous.
These frogs use their poison solely for self-defense, not to kill prey, and what a good defense against predators it is. Many of them are poison dart frogs known for their use in making arrow poisons. Beautiful but deadly – it's definitely a case of look but don't touch with these suckers!

10. Red-backed Poison Frog (Ranitomeya reticulatus)
Ranitomeya reticulatus

The second most poisonous frog in its genus, after the splash-backed poison frog, Peru's red-backed poison frog has a toxicity that is considered 'moderate'. That doesn't mean you can take this little fellow lightly, though: it can still do humans serious injury and kill animals such as chickens. The frog's poison is thought to derive from the neurotoxic venom of the ants it eats and is stored in its skin glands – a great defense against would-be attackers not deterred by its warning colors. Considering the fact that there is only one ground snake (Leimadophis epinephelus) which has a slight resistance to this and other poison arrow frogs' poison, this critter doesn't plan on becoming a meal any time soon!

9. Strawberry Poison Dart Frog (Oophaga pumilio)
Oophaga pumilio (Strawberry poision frog)
With its bright red skin, the tiny strawberry poison dart frog, native to Central America, is one of the most beautiful of the species listed here. Its poison is pretty toxic stuff, causing swelling and a burning sensation, but is still far weaker than that of the Phyllobates genus of poison dart frogs, for example.
The strawberry poison dart frog obtains its particular poison from eating mites. Researchers found that rather than ants, as was previously thought, it is different species of the minuscule arachnids which are the main source of the various toxic alkaloids found in the frog's skin. This means biodiversity in the frog's habitat affects the toxicity of its poison – and thus its ability to ward off predators. Conservation efforts need to take into account not just the frog but the mites that supply its self-defense system.

8. Blue Poison Dart Frog (Dendrobates azureus)
Azure - Blue Dart Frog
This stunning hunchbacked frog may not be as toxic as the deadly Phyllobates of poison arrow fame, but that doesn't mean it isn't dangerous.

The blue poison dart frog's poison can paralyze or kill any predator not warned away by its coloring, and could even potentially prove deadly to a human: 2 micrograms of the toxic compound is enough to be fatal, and the creature can have much, much more than this in its system! However, like all the poison dart frogs, this native of South America is not poisonous in captivity when deprived of its natural diet.

7. Lovely Poison Frog (Phyllobates lugubris)
Also known as the striped poison dart frog, Central America's lovely poison frog is the least toxic in the Phyllobates genus, and yet it still produces dangerous toxins. The amount of toxin is thought to be comparatively low, ranging from nothing to 0.8 micrograms, but this frog is still far from harmless and can cause heart failure in predators that risk eating it. Don't be fooled by its name! (Well, it does look quite lovely.)

6. Golfodulcean Poison Frog (Phyllobates vittatus)
Golfodulcean Frog
The Golfodulcean poison frog is strikingly colored and named for the stripes running down its back. While it is the fourth most toxic of the Phyllobates genus, it contains noticeably less poison than the three species ahead of it in the toxicity stakes. Even so, it's seriously toxic, with poison that can cause excruciating pain, mild seizures, and even paralysis in some cases. It's been reported that tasting this frog (who tastes poisonous frogs deliberately?) leads to "lingering, almost numb sensation on the tongue, followed by a disagreeable tightening sensation in the throat." We're pretty sure that's just the beginning.

5. Splash-backed Poison Frog (Ranitomeya variabilis)
Ranitomeya variabilis
A tree-dwelling species found in the rainforest of Ecuador and Peru, the splash-backed poison frog is the most toxic member of its genus, with the secretions from its skin said to be capable of killing up to five humans. Its mottled coloring may look pretty, but the message is simple: steer clear.

4. Phantasmal Poison Frog (Epipedobates tricolor)
Phantasmal Poison Frog
This killer frog is absolutely tiny but has a toxicity that belies its size. Less than half an inch long in some cases, it packs an incredibly powerful punch. Its poison can easily kill would-be predators and humans alike, but it is also unique due to the fact that a painkiller 200 times more powerful than morphine – called epibatadine – has been developed from it. Endangered in their native Ecuador, Phantasmal poison frogs are being bred in captivity by scientists who are also attempting to maintain their toxicity. Gloves and face masks are a must!

3. Kokoe Poison Dart Frog (Phyllobates aurotaenia)
Kokoe Poison Dart Frog
Phyllobates aurotaenia, also known as the kokoe poison dart frog, is the tiniest of the three most toxic frogs of the genus Phyllobates. Like its sister species, it secretes extremely potent batrachotoxins through its skin. The poison is like acid in its effects, seeping through wounds, and possibly pores, and causing symptoms ranging from unbearable pain and fever to seizures and paralysis. So far there have been no confirmed human deaths, but fatalities are suspected. To obtain the poison of the kokoe poison dart frog and its related species, tribesmen of the Colombian forests impale the frog on a stick and hold it over the fire so that the toxins come to the surface, ready to be rubbed onto their arrow tips.

2. Black-legged Dart Frog (Phyllobates bicolor)
p. bicolor - Black-legged Dart Frog
The second most toxic frog on Earth is the black-legged dart frog, or Phyllobates bicolor, found in western Colombia. It is a little smaller than Phyllobates terribilis and its toxicity is not as strong, but it is lethal all the same. Only 150 micrograms of the poison are needed to kill somebody, and human fatalities have been confirmed. The batrachotoxin causes fevers, excruciating pain, seizures and, ultimately, death by respiratory and muscular paralysis.

1. Golden Poison Frog (Phyllobates terribilis)
Golden Frog
Native to Colombia's Pacific coast, the beautiful but deadly golden poison frog, Phyllobates terribilis, is one of the most poisonous animals on the planet. Small enough to fit comfortably in your palm (though picking it up would be the last thing you'd do!) it nevertheless has enough poison in its skin secretions to kill 10 to 20 men, or two African bull elephants. This frog is rumored to have ended the lives of people who have touched it, while chickens and dogs have died from contact with a paper towel it has merely walked on.

The golden dart frog's poison is a batrachotoxin that kills by blocking the body's nerve impulses, contracting the muscles, and ultimately causing heart failure. The poison also lasts: when the Choco Emberá tribespeople use it for their poison arrows, the arrow tips stay deadly toxic for up to two years.

If you see these gorgeous frogs in captivity, you've less reason to worry – they need chemicals from the insects they eat in the wild to remain poisonous – but as the toxins do not easily deteriorate, we'd definitely keep our distance.

12. Giant Leaf Frog (Phyllomedusa bicolor)
Phyllomedusa - Giant Leaf Frog
This extremely interesting frog, also known as the monkey frog, secretes a mild poison that can have a variety of effects, ranging from sedation and gastric upset to hallucinations. Amazingly, indigenous Amazonian tribes deliberately use it on themselves. The tribespeople apply the poison to self-inflicted burns or other breaks in the skin in order to gain a feeling of refreshment, as well as certain opioid effects. Put simply, this is a frog that can get you high! The giant leaf frog is also under threat from biopiracy because some of its toxic ingredients may be of use in treating AIDS and cancer.

11. Dyeing Dart Frog (Dendrobates tinctorius)
Dyeing Dart Frog
The third largest of the poison dart frogs, at approximately two inches, this big old frog employs poison in self-defense and comes in many different colors and patterns. What is really unique about the dyeing dart frog is the way indigenous tribes of the Guiana Shield make use of it. The tribespeople massage the skin of juvenile parrots with the frog, and the toxic effect of its poison makes the birds' feathers grow in different colors – hence the frog's name. The poison is also used by the tribes for hunting purposes, however, so don't try this at home!

Bonus: Corroboree Frog
Corroboree frog
The corroboree frogs are found in sub-alpine areas of Australia (yes, there is such a thing!) and are easily recognizable by their clear yellow stripes. Unlike all the other frogs on this list, they actually produce their poison by themselves – and are the first invertebrates discovered that can do so. The rest all gain their toxicity from their diet of bugs and insects. Critically endangered, partially due to drought and habitat destruction, this beautiful but poisonous amphibian is the subject of an ongoing conservation effort.

Source: environmentalgraffiti.com


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