The 5 differences between toxic and poisonous

These are the characteristics that allow us to distinguish between toxic and poisonous substances.

The words toxic and poisonous are often used interchangeably in popular language. Many of us think of them as synonyms, usually used to refer to an animal, plant or fungus having a chemical compound that is harmful.

While this definition is the closest to the popular one, the truth is that, if we spin a little finer we can find differences between toxic and poisonousbeing very important for the world of biology.

Next we are going to see which are the differences between these two words, relating it especially with the animal world.

Differences between toxic and poisonous: learning to distinguish between the two concepts.

In nature, there are countless animals that synthesize their own chemical compounds as a method of defense against predator attacks or, also, as a strategy to prey on other animals.

The synthesis and use of these substances is a very effective but also expensive strategy: nothing in the animal world is free and producing toxins is less so.especially if we take into account that the food that provides them with the substances and energy to produce them is not always available.

Many evolutionary biologists believe that the ability of certain species to produce toxins is attributable to the randomness of the genome. Surprising as it may seem, it is believed that throughout the history of evolution it has happened that an individual of a species, by mere chance, has suffered some kind of mutation in its genetic code that has caused it to synthesize a protein in a normal way instead of doing so with an alteration.

It may happen that after the mutation, the new substance is toxic to other animals, which means that the individual that has it is protected or has a certain advantage within its species and environment. If it used to be an easy prey, it is now an indigestible prey for its predator and, if it used to have to hunt for food, it now has an element that allows it to kill its victims more quickly.

Synthesizing a toxicant is an advantageous trait that makes individuals with the mutation more likely to survive and reproduce.. This will progressively make the capacity to produce the poison become a generalized capacity in that species thanks to natural selection, fixing the trait in the species, although this does not mean that the species is toxic and/or poisonous. These two words applied to living beings have their differences, which we will see below.

What is the difference between a toxic and a poison?

To understand the differences between what is toxic and what is poisonous, it is necessary to make a brief comment on what these two words mean in general terms. In Spanish, we use the terms "toxic" and "poisonous" as if they were synonyms and, generally, when we use them to describe an organism we want to indicate that this animal, plant, fungus or other has a chemical component that can be harmful to other living beings.

On the other hand, other languages do distinguish between the two, other languages do distinguish between the two conceptsThis is the case of the English language. In this language there are the words "venomous" and "poisonous", which are used differently depending on the characteristics of the animal when using its toxins. These differences will be discussed in more detail below.

1. Toxin is the unit, poison the combination.

The toxin would be the unit, while the poison would be the combination of several of them. A toxin is a harmful substance produced by an organism, which can cause harm to another living being.

Here we can understand the first difference between a toxin and a poison: a poison is composed of one or several toxins, whereas the toxin itself is simply a functional unit that can give rise to different types of poisons.

Toxins are usually peptides composed of several amino acids that are joined together by peptide bonds and give rise to a protein. When a toxin is formed by a long chain of complex amino acids, we say that we are dealing with a toxic protein..

An example of a toxic protein would be ricin, produced by the species Ricinus communis which contains two chains with more than 260 amino acids each. In other words, it would be a poison composed of a single toxin.

Another different case would be the venom of the scorpion Androctonus bicolorwhich has up to 103 unique toxic peptides. This means that the venom of this arachnid is composed of more than 100 toxins.

2. The venom attacks, the toxin is passive.

Poisonous animals inject poison, while toxic animals simply contain toxins but do not have to use them voluntarily.. We can say that the poison is used as a weapon, it "attacks", while the toxin is simply found in the animal's organism, in a more or less passive way.

For an animal to be considered poisonous, it should present some element in its anatomy that allows it to inject toxic compounds into the bloodstream of its victim, either jaws, fangs, spurs or stings...

3. Toxic animals do not inject toxins.

Related to the previous point, we can say that those animals described as toxic do not present limbs that serve to inject a poisonous substance. Many amphibians produce toxins, but they do not have anything to attack with or make voluntary use of them, so they cannot be considered poisonous.

An example of a particularly toxic amphibian is the case of dendrobates frogs (Dendrobatidae), which have neither stingers nor fangs nor any system for inoculating their potent toxins. Instead, they secrete their toxic compounds through their skin naturally, causing discomfort and severe symptoms to anyone who dares to lick them.

4. Toxic animals warn, poisonous animals go unnoticed.

Toxic animals warn all potential predators that they are not going to like what they are going to find, while poisonous animals go unnoticed.Poisonous animals tend to do just the opposite, hiding and going unnoticed.

This is because many toxic animals are rarely predators, being rather animals that do not have great strength, size or defensive limbs. Since there is little they could do in the face of a predator's bite, their organism has adapted to warn them not to dare to do so, because if they do, they run the risk of becoming intoxicated.

The best way to warn them is by visual signals, the most striking being the use of bright colors such as blue, yellow, green and phosphorescent white on a black background, as is the case of many dendrobates frogs. This is also observed in some plants and fungi, and this phenomenon is called aposematism.

On the other hand, venomous animals are usually predators that use their toxins to weaken their victim while hunting, making the process of depredationThis makes the predation process quicker and less energetically costly. Therefore, it does not pay to attract the attention of their victim and many venomous species have colors that allow them to camouflage themselves with the environment.

Venomous snakes are an example of this. It doesn't matter if we are in the desert, in the countryside, in the jungle or in the savannah. Whatever the environment, we will find this type of reptiles whose coloration will make them camouflage themselves very well so that their victims do not see them, even when they are being attacked with their venom.

5. Neither toxic nor poisonous: toxogens

Apparently, not all toxin-producing animals are toxic or poisonous.. There are animals that produce toxins and contain them in their organism, they cannot inject them but they can make a defensive and voluntary use of them: toxungenous organisms.

In this category we would find animals that produce toxins but do not inject them by means of jaws, fangs or stingers, but neither do they wait to be ingested or touched to release them.

An example of a toxigenic animal would be skunks (Mephitidae).. These animals are known to expel a foul-smelling chemical substance from their anal glands when they feel threatened. This substance is harmless in humans, but very harmful to domestic animals such as dogs and cats, which, after smelling it, may suffer vomiting, dizziness, temporary loss of vision and other serious symptoms.