What is the slowest acting venom?
Five surprisingly venomous animals
Venom is usually associated with insect stings and reptile bites.
But this versatile, injectable substance is also used to attack or defend by a number of animals — including some you might not expect.
Slow lorises (above) are the only venomous primates. They have become an internet sensation thanks to videos of them raising their arms to be ‘tickled’. However, a slow loris with its arms raised is actually taking a defensive posture.
The primate raises its arms for easy access to the toxin-producing brachial gland under its arm. The animal licks the gland, because mixing the toxin with saliva is how its bite becomes venomous.
Sadly, the slow loris is frequently illegally traded, sold across the world as an exotic pet.
To avoid a bite that can lead to anaphylaxis and death in humans, traders often clip the animal’s teeth. Many slow lorises die as a result of blood loss or infection from these procedures.
Another remarkable thing about this primate is its colouration. It is thought that the patterns on its fur developed to mimic the colouration of cobras, helping it to prevent predator attacks.
The platypus is one of only five species of egg-laying mammals, known as monotremes. All monotremes are native to Australia and New Guinea.
The platypus has a range of features that make it quite unlike any other animal.
With a large bill, a paddle-like tail, webbed feet and a furry body, this funny-looking animal produces venom that evolved to cause pain, mainly in other platypuses.
Male platypuses possess a sharp set of spurs on their hind heels and use their venom against other males to maintain their territory. The venom is produced seasonally, increasing in the mating season.
Humans who have been envenomed by a platypus experience excruciating pain that, while non-fatal, also can’t be eased by traditional painkillers like morphine.
Female mosquitoes feed on blood through a needle-thin and straw-like proboscis, although the resulting itchy red lump on the skin is referred to as a bite.
The mosquito pierces the skin and searches for a blood vessel, then injects saliva into the wound. Full of anti-coagulants, the saliva prevents the wound from closing, allowing the insect to drink its fill.
As an injectable substance, mosquito saliva can be considered a type of venom.
However, the red lump isn’t caused by the venom but the human body’s response to it. To fight the saliva, the body produces histamines that cause the blood vessels in the affected area to swell, resulting in the lump.
Mosquito venom may not be particularly dangerous, but the diseases these insects can harbour often are.
Malaria kills 600,000 people every year, and an additional 12,000 deaths are caused by yellow fever. Mosquitoes can also carry dengue and Japanese encephalitis among many other diseases.
Shrews are small, mole-like mammals that are sometimes mistaken for mice. But unlike most other mammals, some shrew species are venomous. One of these is the American short-tailed shrew (Blarina brevicauda).
Venom can be transferred in many ways, including through spines, stingers or claws.
Unlike many venomous animals’ teeth, which are hollow, shrews’ teeth feature a groove along their sides, acting as a channel for the venom’s delivery.
Shrews are thought to mainly use their venom for immobilising the small insects and earthworms they prey on.
In this instance, venom is a kind of preservative. The prey are paralysed and stored in the shrew’s burrow. Paralysing the prey — as opposed to simply killing it — keeps food fresher for longer, after all.
Shrews eat at least their own body weight in food each day. Without the ability to store food this would be difficult for the mammal to achieve, especially in winter when supplies are scarce.
Cone snails are a group of predatory sea snails. With colourful shells, these molluscs come in a variety of sizes and feed mainly on worms, although some have evolved to feed mainly on fish.
Their elegant appearance belies a remarkably effective hunting technique. Cone snails have a hypodermic needle-like tooth to inject their prey with paralysing venom. The tooth is launched like a harpoon, latching onto the unlucky victim. Some species are even equipped with a backwards-facing barb.
Their venom is a cocktail of toxins that paralyses their prey.
But the geography cone (Conus geographus) first disperses its toxins through the water. This is absorbed through the gills of its prey, causing them to become disorientated and enter a state of hypoglycaemic shock.
Then the cone harpoons the prey, leaving the fish to struggle for only one or two seconds before it is paralysed.
The venom of the fish-hunting geography cone is potent enough to kill humans, making this unassuming-looking mollusc one of the most venomous animals on Earth.
Why cats have more lives than dogs when it comes to snakebite
Date: May 18, 2020 Source: University of Queensland Summary: Cats are twice as likely to survive a venomous snakebite than dogs, and the reasons behind this strange phenomenon have just been revealed. The research team compared the effects of snake venoms on the blood clotting agents in dogs and cats, hoping to help save the lives of our furry friends. Share:
Cats are twice as likely to survive a venomous snakebite than dogs, and the reasons behind this strange phenomenon have been revealed by University of Queensland research.
The research team, led by PhD student Christina Zdenek and Associate Professor Bryan Fry, compared the effects of snake venoms on the blood clotting agents in dogs and cats, hoping to help save the lives of our furry friends.
«Snakebite is a common occurrence for pet cats and dogs across the globe and can be fatal,» Dr Fry said.
«This is primarily due to a condition called ‘venom-induced consumptive coagulopathy’ — where an animal loses its ability to clot blood and sadly bleeds to death.
«In Australia, the eastern brown snake (Pseudonaja textilis) alone is responsible for an estimated 76 per cent of reported domestic pet snakebites each year.
«And while only 31 per cent of dogs survive being bitten by an eastern brown snake without antivenom, cats are twice as likely to survive — at 66 per cent.»
Cats also have a significantly higher survival rate if given antivenom treatment and, until now, the reasons behind this disparity were unknown.
Dr Fry and his team used a coagulation analyser to test the effects of eastern brown snake venom — as well as 10 additional venoms found around the world — on dog and cat plasma in the lab.
«All venoms acted faster on dog plasma than cat or human,» Mrs Zdenek said.
«This indicates that dogs would likely enter a state where blood clotting fails sooner and are therefore more vulnerable to these snake venoms.
«The spontaneous clotting time of the blood — even without venom — was dramatically faster in dogs than in cats.
«This suggests that the naturally faster clotting blood of dogs makes them more vulnerable to these types of snake venoms.
«And this is consistent with clinical records showing more rapid onset of symptoms and lethal effects in dogs than cats.»
Several behavioural differences between cats and dogs are also highly likely to increase the chances of dogs dying from venomous snake bite.
«Dogs typically investigate with their nose and mouth, which are highly vascularised areas, whereas cats often swat with their paws,» Dr Fry said.
«And dogs are usually more active than cats, which is not great after a bite has taken place because the best practice is to remain as still as possible to slow the spread of venom through the body.»
The researchers hope their insights can lead to a better awareness of the critically short period of time to get treatment for dogs envenomed by snakes.
«As dog lovers ourselves, this study strikes close to home but it also has global implications,» Dr Fry said.
«I’ve had two friends lose big dogs to snakebites, dying in less than ten minutes even though the eastern brown snakes responsible were not particularly large specimens.
«This underscores how devastatingly fast and fatal snake venom can be to dogs.»
9 of the World’s Deadliest Snakes
John P. Rafferty writes about Earth processes and the environment. He serves currently as the editor of Earth and life sciences, covering climatology, geology, zoology, and other topics that relate to.
John P. Rafferty
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Encyclopaedia Britannica’s editors oversee subject areas in which they have extensive knowledge, whether from years of experience gained by working on that content or via study for an advanced degree. They write new content and verify and edit content received from contributors.
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Few animals strike as much fear into people as venomous snakes. Although the chances of running into a venomous snake, much less being bitten and dying from the toxin injected into one’s body, are miniscule compared to dying from cancer, heart disease, or an automobile accident, this seemingly unreasonable fear remains very real for many people. The snakes described here live primarily in tropical regions, but some might be living in research centers and zoos near you.
A dangerous African snake named for its black mouth
The “black,” or black-mouthed, mamba (Dendroaspis polylepis) inhabits rocky savanna and can often be encountered on the ground, where it seems to be fond of termite mounds. Ranging in color from gray to dark brown, its name derives from the blackened inside of its mouth. The black mamba is feared because it is large and quick, and it possesses an extremely potent venom that kills most of its human victims. Despite its aggressive reputation, unprovoked attacks on humans have not been proved, and it is responsible for only a small number of deaths annually.
The barba amarilla (“yellow chin”) of Latin America
The venom of some species, including the Okinawa habu (T. flavoviridis), an aggressive snake that often enters human dwellings in the Ryukyu Islands, is mildly dangerous. On the other hand, the venom of the terciopelo (B. asper), the fer-de-lance of Central America is necrotizing, painful, and often deadly. Other dangerous fer-de-lances include the jararaca (B. jararca) of Brazil and the wutu (Bothrops alternatus) of Argentina.
One of the most dangerous snakes in Africa
The boomslang (Dispholidus typus) hunts by extending the forward part of its body motionless from a tree, its form mimicking a branch. A rear-fanged snake, it delivers its venom by chewing on its victim until the victim succumbs to the toxins.
The quintessential Australian cobra
The eastern tiger snake (Notechis scutatus) is the most widely distributed type of tiger snake, which inhabits the southern fringe of Australia and the region’s nearby islands. As it prepares to strike, it flattens its head and neck in a manner similar to Asian and African cobras.
The killer of the most people
The saw-scaled viper (Echis carinatus) may be the deadliest of all snakes, since scientists believe it to be responsible for more human deaths than all other snake species combined. Its venom, however, is lethal in less than 10 percent of untreated victims, but the snake’s aggressiveness means it bites early and often.
A dangerous snake with a triangular-shaped cross section
The banded krait (Bungarus fasciatus) is a highly venomous relative of the cobra. Its venom is essentially a neurotoxin that induces paralysis.
The longest venomous snake in the world
The king cobra (Ophiophagus hannah) is the longest venomous snake in the world. Its bite delivers a tremendous amount of paralysis-inducing neurotoxins. The snake’s venom is so strong and so voluminous that it can kill an elephant in just a few hours. Death also results in at least 50 to 60 percent of untreated human cases.
The largest relative of the cobra in Australia
The coastal taipan (Oxyuranus scutellatus) produces venom that is nearly identical to that of its inland cousin. Its bite is lethal in more than 80 percent of untreated cases.