WHAT do a tiny spider and a jellyfish with 10-foot-long tentacles have in common? Both produce toxins that could kill within minutes.
The poison contained in some animal bites can eat away at your skin, freeze your muscles, or cause your heart to stop beating entirely.
Neurotoxins are among the most widely studied classes of toxins. They eat away at nerve tissue, hindering functions like the ability to think, move, or breathe.
These toxins naturally occur in the human body, with the neurotransmitters nitric oxide and glutamate being two examples.
While they play an essential role in cell communication, high concentrations of neurotoxins can cause irreparable damage.
Scorpions, many types of snakes, and the blue-ringed octopus all produce neurotoxic venom. In pufferfish, the toxin is called tetrodoxin.
Neurotoxins are also found in the bite of the redback spider, which is counted among the deadliest arachnids in Australia.
Next are cardiotoxins, which target blood plasma and muscles of the heart. They bind to receptor sites on the surface of these cells and prevent muscle contraction.
Consequently, these toxins may cause the heart to beat irregularly or stop beating altogether, which can be fatal. This resulting heart dysfunction is medically known as cardiotoxicity.
While many snakes produce cardiotoxins in their venom, one standout is the Australian box jellyfish, with a sting considered one of the deadliest in the world.
If more than 10% of a person’s skin is affected by box jelly venom, cardiac arrest can occur in just minutes. Children are particularly at risk.
This deadly venom is why the box jelly is regarded as the most dangerous marine animal in the world.
Next are hemotoxins, which specifically target blood cells and blood vessels.
These toxins have a range of effects, from preventing oxygen from being carried throughout the body to causing internal bleeding.
Hemotoxin-containing venoms trigger swelling, cardiovascular damage, and eventual necrosis, or tissue death.
Tiger snakes, one of the most common species in Australia, have hemotoxic venom, as well as a variety of jellyfish and spiders.
Myotoxins, found in the venom of animals like the king brown snake, can be devastating. These break down muscle fibers near the injection site, causing paralysis.
Necrotoxins are so-called for causing cell death, or necrosis. A bite may cause the skin to blacken, indicating that the tissue has died.
The brown recluse, puff adder, and most rattlesnakes and vipers all have necrotoxic venom.
It is also worth noting that bacteria can produce necrotoxins as well. In fact, an infection called necrotizing fasciitis is caused by a “flesh-eating” bacterium.
Coagulotoxins impair the blood’s ability to clot, causing prolonged or extended bleeding.
Varieties of snake venom, namely that of the eastern brown snake and spitting cobras, contain coagulotoxins. Deaths due to hemorrhage after a snake bite have been noted in scientific literature.
Next are cytotoxins, which occur naturally in the human body as part of the immune system.
They come in the form of killer T cells – white blood cells that destroy cancer cells and those infected by viruses or bacteria. However, cytotoxins in a snake bite might degrade otherwise healthy cells.
Some animals boast several different types of toxins in their venom. Mohave rattlesnakes, for instance, produce both neurotoxins and myotoxins, making their bites twice as potent.
Scientists believe animals use venom to kill or weaken prey and protect themselves from predators.
A 2020 study from Bangor University found evidence that snake venom is more likely to assist in hunting and less in defense.
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