Toxic Turtles and a Man-Killing Frog: 5 Damp and Deadly Natural Poisoners

Many wild animals are dangerous, but not all of them kill with tooth and claw - some are surprisingly sophisticated poisoners and a serious threat to an unwary human. Let's take a look at...

• The Deca-Deadly Golden Poison Dart Frog
• The Brilliant Blue-Ringed Octopus (and a Flamboyant Cuttlefish)
• The Cloud-Killing Cone Snails
• The Stealthy (and Spiky) Stonefish
• The Terribly Toxic Hawksbill Sea Turtle

The Deca-Deadly Golden Poison Dart Frog

Weighing in at a mere 30 grams (that's around the weight of a packet of potato crisps or chips) the golden poison dart frog doesn't seem that intimidating... but pick one up in the wild and you'll find they punch well above their weight. This diminutive amphibian dwells in the humid rainforests of Colombia and can carry enough poison to kill 20,000 mice or 10 people - hence its scientific name "Phyllobates terribilis."

This frog may be one of the most poisonous animals in the world, but it doesn't actually produce its own toxins. Instead, the amphibian stores poison from the insects it feeds on... which means that they can lose their toxicity in captivity thanks to a change in diet!

The Brilliant Blue-Ringed Octopus (and a Flamboyant Cuttlefish)

Did you know that blue-ringed octopuses don't always show their colors? Like other cephalopods, they possess chromatophores (special "color" cells) that make their skin chameleonic... and they break out the brilliant blue rings when they feel threatened.

Researchers have suggested that there may be around ten different species of blue-ringed octopuses. Their signature trick (other than the rings) is a store of tetrodotoxin, which is produced by symbiotic bacteria living inside the octopus. Not only does this potent paralytic neurotoxin (suggested to be far more powerful than cyanide - an almost painless bite can deliver a fatal dose for a human) get administered by a bite, it disperses throughout the cephalopod's body and can give predators a terminal case of indigestion.

The blue-ringed octopus packs a punch, but it's not the only secretly sinister cephalopod out there. The flamboyant cuttlefish (Ascarosepion pfefferi) may only reach 8cm in length, but it doesn't back down from threats - instead, it waves its fins and pulses its colors. This death-wish isn't what it seems - the flamboyant cuttlefish is armed with venom as deadly as the blue-ringed octopus!

The Cloud-Killing Cone Snails

Would it surprise you to learn that one of the most sophisticated poisoners of the animal kingdom is a predatory marine snail?

Cone snails are predatory mollusks that use venom to subdue moving prey. Their venom varies in strength, but the ones that hunt fish tend to have the strongest - and it is these examples that are the most dangerous to humans.

The geography cone snail (its shell pattern looks a bit like an old atlas) is one of these piscivores... and it comes with not one but two poison delivery systems. The first is an ability to release an insulin cloud into the water, something that can subdue passing fish. The insulin is absorbed through the gills and swiftly drops the victim's blood sugar levels, plunging them into hypoglycemic shock. The snail can then approach at a leisurely pace before injecting the target with a lethal cocktail of venom.

The poison of a cone snail can be potent, with around 30 confirmed human deaths attributed to stings from these small mollusks. On the plus side, elements of the venom may have pharmaceutical uses as a powerful morphine alternative!

The Stealthy (and Spiky) Stonefish

Stonefish get their name from the fact they look like... well, a stone. Step on one of these living rocks though and you might not live to regret it!

The reef stonefish is arguably the most venomous fish in the world, deploying an agonizing venom through a series of pressure-activated dorsal spines... which means that standing on them will fill your foot with poison.

It's thought that plenty of Pacific and Indian Ocean islanders have died to the venom throughout history, as the venom is certainly capable of killing an adult human. That said, fatalities are quite rare in modern times - an antivenom was developed in 1959, and the spines of the fish can be mostly avoided by "shuffling" along the bottom rather than taking bold steps. A sting can even be treated by immersing the area in hot (not scalding) water, as this denatures (breaks down) the venom.

That said, you may wish a sting would prove immediately fatal - the pain is intense, and has been described as sledgehammer blows working their way up a limb over the course of an hour!

The Terribly Toxic Hawksbill Sea Turtle

Have you ever wondered if a turtle can be toxic? The answer is yes, and we even have a name for turtle-based poisoning - chelonitoxism.

Marine turtles that snack on certain foods can become very dangerous for humans to eat. They can collect any heavy metals or pesticides that contaminate their meals, which get added to toxins from the blue-green algae on which they feed. The result is a cocktail of harmful substances spread through the meat, one that can cause fatal food poisoning in humans.

Hawksbill sea turtles are particularly risky meals. In 2010, a single hawksbill caused a massive food poisoning outbreak in the Federated States of Micronesia (a sovereign nation in the Pacific.)

Despite being line-caught and being kept healthy and alive until the day of cooking (it was turned into a stew) it soon became apparent that something was horribly wrong with the meat.

Approximately 84% of those who partook of the turtle became ill - 95 people were reported as sickened, while four children and two adults died as a result.

Thanks for reading - perhaps you'd also like...

• Flamingo Whirlpools and Scorching Spiders: 5 Cunning Tactics in the Animal Kingdom
• Explore 13 Unbelievably Weird Weapons in the Animal Kingdom
• 7 Out-of-This-World Animals So Strange They Seem Alien

Sources and Further Info:

• Golden poison dart frog
• Golden Poison Frog
• The blue-ringed octopus: small, vibrant and exceptionally deadly
• Flamboyant cuttlefish
• What is the most venomous animal in the world?
• How Toxic is the Stonefish?
• Reef Stonefish
• Mass poisoning after consumption of a hawksbill turtle, Federated States of Micronesia, 2010