Explained: Poison vs Venom
Alistair Gamblin
One of the most common subjects of confusion when it comes to wildlife seems to be the use of poisonous and venomous and interchangeable, or like-for-like terms. It’s a misconception I find so frustrating, I’ve had to write an article about it! So, what is poison and venom, and does confusing them really make a difference? Well, yes! Here’s why:
Poison-
Poison is used across the natural world, often as a method of defence. It is seen in a huge variety of different flora and fauna, including in some mammals, and there is even a species right here at the Menagerie which also possesses this lethal trait: the Phantasmal Poison Dart Frog (Epipidobates anthonyi). The poison of these frogs is so potent, it has even led to their name, the word ‘dart’ referring to the way in which the native tribes of South and Central America have for generations rubbed the frogs on the tips of their hunting arrows.
For an animal’s poison to be effective, it must be consumed by the victim, be they predator or prey. This could be through absorption, inhalation or ingestion. Once the poison has entered the body it sets to work causing severe injury by targeting the body’s cells, often with fatal consequences. In the case of our poison dart frog, they carry some of the most potent of all known natural toxins, which they can secrete through their skin with deadly effects. Although unassuming in size, an unfortunate encounter with one of these striking animals will send deadly batrachotoxins coursing through the body, gradually impacting nerve and muscle cells with irreversible effects. Some species of dart frog are so toxic, that a single individual could be fatal to several adult humans!
Many poisonous plant and animal species have bright, obvious colours and patterns to serve as a warning to any potential threats. Sticking with our dart frog example, this method- known as aposematism- is highly effective, and often limits the risk these species face, allowing them to hunt and live successfully in some of the world’s most challenging environments.
Venom-
Venom can easily be just as deadly, but its delivery is very different. Unlike the passive method of transfer used by poisonous species, animals with venomous capabilities must actively inject their substance into the victim. Often this is through bites and stings. Whilst we have no venomous species within our collection, there are still plenty of examples in the natural world. Among the animals most associated with venom are snakes, with around 600 species armed with the toxins. This being said, only a select few can cause serious harm to the average person.
One of the largest and deadliest is the King Cobra (Ophiophagus hannah). They use their long, curved fangs to sink into their prey- or in defence against a potential threat- delivering a lethal quantity of potent venom. Venom is mostly made of proteins, many of which have specific targets in the body, such as the blood or brain, often impacting the body’s core systems. The venom of a King Cobra is known as a neurotoxin, one of the most common venom types. It specifically impacts the central nervous system of the victim, often leading to paralysis, and eventually death.
As venom is primarily constructed of proteins, they can often be neutralised by the digestive system, so ingestion would not be an effective method of envenomation. This- along with some specialised adaptations unique to different species- is how the King Cobra can consume other venomous snakes, and species like the Secretary Bird can also kill and eat the otherwise deadly reptiles without ill effects.
So, what’s the difference?
To summarise, there is one clear difference between poisons and venom: how they enter their victim. Poisons are ingested into the body of the victim, whereas venom is actively injected by the attacker, through bites and stings.