All things are poisons, for there is nothing without poisonous qualities.

It is only the dose which makes a thing poison.

(Paracelsus)

There are many animals which are poisonous like frog, beetle, salamander, snake etc. They use toxic chemicals to defend themselves. but we often think about, why don’t they die of this poison? The answer is that they use one of two basic strategy
  1. They securely store these compounds in different pouches/chambers.
  2. They get immune (evolve resistance) to those compounds.
There are different mechanisms for different animals. For example, if we talk about one of the poisonous beetle “Bombardier beetle” they spray poisonous liquid from the glands of it’s abdomen eject at 100°C.  This beetle uses first strategy i.e “they securely store these compounds in different pouches/chambers” Poisonous animals When they are threatened they mix the chemicals in different pouches within their body and spray them on the enemy. Similarly Jelly fish pack their venom safely in the harpoon like structure called Nematocysts. These Nematocysts are small stinging cells which are present on the tentacles of the jellyfish. When the external stimulus, threat or prey touch its tentacles, Nematocysts eject and paralyze its prey. Tentacles Mostly Jellyfish stings are painful but some are deadly. For example, there is a sea wasp, its nematocysts release venom which can cause contraction of the heart muscles and rapid death in large doses. Although, there is antidote, but the venom is fast-acting, so you need medical intervention.

Venomous snakes

These snakes have very powerful venom. It can clot your blood when injected even it can eat your flesh. They have specialized compartments in their mouth, they only exit through their fangs. Snakes also employ the second strategy. i.e “Built in biochemical resistance”. Rattle snakes and other type of viper snakes make special type of protein that bind and inactivate venom in their blood.

Dart Frog

Meanwhile, other animals like poisonous dart frog are resistant to their own poison but they are using different mechanism. These frogs defend themselves using bitter-tasting compounds known as “Alkaloids”. They accumulate Alkaloids by eating Ants and other small arthropods. One of the most strongest alkaloid is the chemical “Epibatidine” which binds to the same receptor in the brain as Nicotine but it is ten times stronger than Nicotine. Its small amount (equals to sugar grain) can even kill you. Let me explain you this mechanism with an example. Consider the Receptor of our brain is a lock and the specific alkaloid “Epibatidine” is a key. so this alkaloid key is only fit in a specific lock (receptor) of the brain. and this lock is same lock where we can also use “Nicotine” key. but alkaloid Epibatidine is 10 times more powerful than nicotine. In those animals who derive resistance, they actually change the structure of their lock (receptor) so the key (toxin) could not affect them. Consequently, different animals are using different mechanisms to protect themselves. But they are using special defensive mechanism to protect their own body from being eaten by that venom. Even, their venom become intense after passing it to different generations due to Genetic modification so as there body resistance increases as well.
FASCINATING SCIENCE MAG