batrachotoxin

Nature’s Moste Potente Potion – Golden Poison Frog

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For those of you wondering about the title, no it is not a typo. It is an obscure Harry Potter reference, and if you got it, I applaud you.
Remember that golden poison frog (Phyllobates terribilis) I mentioned in the last article about the hooded pitohui? Well, I thought it should get its very own entry because it’s just such a cool little thing. As I mentioned before, it is one of the few animals that carries the deadly batrachotoxin. It gets this poison from the beetles and ants it eats just, like the pitohui does. The frog, however, is much, much, much more dangerous! You can even get this from its Latin name – “terribilis” speaks for itself. So before I explain how toxic it is, let’s find out where they live and what they’re like so if you ever travel there, you can keep an eye out and avoid them like the plague.
The golden poison frog is found exclusively in the rain forests of Colombia in South America. Instead of living on the forest floor like many other poison frogs, it lives in the trees up to about eight feet above the ground. These poison frogs do come down occasionally, especially when feeding, but generally stick to high up plants. They don’t use bromeliad pools to lay their eggs, so they need to come down to the ground in order to reproduce as well. When the eggs hatch into tadpoles, the parents transport them to water filled tree hollows where they can metamorphose. Golden poison frogs, like other poison frogs, are very social animals and live in groups with up to several individuals in captivity.

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Now the part about their poison. Like I said, it is much stronger than the pitohui’s. It is a very important killing tool to the native people of Colombia when they hunt. Pinning a frog with a stick and rubbing a heated dart across its back can keep the dart effective for two years afterward. Some tribes even keep several of these frogs in woven baskets for their poison, but they must take great care in doing so. Inevitably, there are cases where people have died from accidentally touching a captured frog. The average frog contains around one milligram of poison, which is enough to kill up to 20 adult humans or two male African elephants. This can be translated to 15,000 humans per gram of poison. Not only is the poison toxic while on the frog itself, but it can last once rubbed off as well, as in the case of the poison darts. It is absorbed through the skin, so simply brushing against a frog or something its skin has touched can kill. Batrachotoxin attacks sodium ion channels on cells within the central nervous system, which causes paralysis of pretty much everything including the heart and lungs. This can lead to death for a person in five minutes. The golden poison frog has special sodium channels that aren’t affected by batrachotoxin, which is why it can carry such a deadly substance around without any harm to itself.

Ball and stick model of batrachotoxin’s molecular structure.

Funnily, these frogs are often kept by amphibian hobbyists as pets. It’s okay, though, because captive raised frogs aren’t toxic at all and can be handled freely for as long as the animal will tolerate it. All the poison comes from their diet and captive frogs’ diets are devoid of the prey that gives them their deadly defense. However, wild caught golden poison frogs are dangerous. Even after a change of diet, the toxins can linger in the frog’s body for years afterward, so it is inadvisable to keep anything but a captive bred golden frog. As the name states, they obviously come in a lovely, bright gold color, but there are also a variety of other color morphs. These include the orange morph and mint morph.

Mint morph

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Orange morph by John Clare on Flickr.

As beautiful as golden poison frogs are, stay well away if you ever go to Colombia and find one! You wouldn’t even be able to be sorry if you got too close because you’d be dead.

References:
1. Gratwicke, Brian. “Golden Poison Frog.” WAZA. World Association of Zoos and Aquariums, n.d. Web. 25 June 2015. <http://www.waza.org/en/zoo/choose-a-species/amphibians/frogs-and-toads/phyllobates-terribilis&gt;.

2. Patocka, Jiri, Kräuff S. Wulff, and María V. M. Palomeque. “Dart Poson Frogs and Thier Toxins.” Ed. Colonel R. Price. The ASA Newsletter 74 (1999): n. pag. Applied Science and Analysis. Web. 24 June 2015. <http://www.asanltr.com/ASANews-99/995frogs.htm&gt;.

3. Stuart, Sean K. “The True Poison-Dart Frog: The Golden Poison Frog.” Frogs. Herpetologic.net, n.d. Web. 24 June 2015. <http://www.herpetologic.net/frogs/caresheets/terribilis.html&gt;.

4. Alvarez, Mariela C. and Wiley, Mary. “Phyllobates terribilis”. Animal Diversity Web. University of Michigan Museum of Zoology, 20 Aug. 2011. Web. 24 June 2015. http://animaldiversity.org/accounts/Phyllobates_terribilis/

5. Wunderli, Michael. “Golden Poison Frog (Phyllobates Terribilis)” Encyclopedia of Life. Eol.org, n.d. Web. 25 June 2015. <http://eol.org/pages/1039238/details&gt;.

Photo Links:
1.https://flic.kr/p/6wgLdn

2.http://www.batrachotoxin.com/batrachotoxin720.gif

3.http://vignette4.wikia.nocookie.net/reptiles/images/4/44/Cuddling_Terribilis.jpg

4.https://flic.kr/p/QdySzj

The Poison Bird – Hooded Pitohui

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The hooded hitohui (Pitohui dichrous) of Papua New Guinea is one of the world’s first and only documented poisonous birds. It was discovered to be toxic during a 1989 study of birds of paradise by American ornithologist John “Jack” Dumbacher. He and his team had mist nets set out to catch birds of paradise, but inevitably, other birds were caught in the nets as well. Some of these birds were hooded pitohuis, which would bite and scratch defensively when being extracted from the mist net. Dumbacher got a bite from one of the birds on his finger that started to sting, so he decided suck on the cut to clean it. After about a minute, his lips and tongue started to tingle and burn. This happened to several other volunteers as well so the team wondered if the pitohui was the cause. When more pitohuis were captured, Dumbacher took a feather and put it directly on his tongue, finding that the burning and tingling effects could last for hours. When he returned to America, Dumbacher took some feathers to chemist John Daly at the National Institute of Health. By 1992, Daly discovered that the feathers contained batrachotoxin. It is an extremely powerful steroidal alkaloid poison that is largely neurotoxic, and even relatively small doses can lead to paralysis of all muscles, cardiac arrest, and then death. This is the most toxic natural substance known and is also present in the secretions of several poison dart frogs of the genus Phyllobates (most famously, Phyllobates terribilis – the Golden Poison Frog).

Credit: Brendan Freeman (Wikimedia Commons)

At first it was not known how this bird acquired such a potent toxin, but locals of New Guinea were asked what they knew about hooded pitohuis and relayed their observations. Pitohuis often catch and eat small and colorful Choresine beetles from the Melyridae family. The same toxin has previously been found in these beetles, which are also known to be preyed upon by Phyllobates poison dart frogs. The striking orange and black feathers of the hooded pitohui are another indication of its toxicity. Many poisonous and venomous animals are brightly colored to warn potential predators that they are very dangerous and not to be messed with. This is called aposematic coloration. Any animal unlucky enough to catch a pitohui would quickly learn to stay away when it sees those colors again. Of course, the bird has not always had this defense. First it had to evolve to cope with the poison itself before being able to incorporate the toxin as part of its own defense. It is likely that the first pitohuis that fed on melyrid beetles only ate a few at a time, slowly building up a resistance to batrachotoxin over generations. This toxin has been found in not only the bird’s feathers, but also its flesh.

This amazing, colorful bird just goes to show that even the most seemingly harmless animals can have alarming tricks up their sleeves.

References:
1. Dumbacher, John P., et al. “Homobatrachotoxin in the genus Pitohui: chemical defense in birds?.” SCIENCE-NEW YORK THEN WASHINGTON- (1992): 799-799.

2. Dumbacher, John P., et al. “Melyrid beetles (Choresine): A putative source for the batrachotoxin alkaloids found in poison-dart frogs and toxic passerine birds.” Proceedings of the National Academy of Sciences of the United States of America 101.45 (2004): 15857-15860.

3. “Jack Dumbacher.” California Academy of Sciences. N.p., n.d. Web. 24 June 2015. <http://www.calacademy.org/explore-science/jack-dumbacher&gt;.

Photo Links:
1. https://commons.wikimedia.org/wiki/File:Hooded_Pitohui_3.jpg