What kind of poison can an octopus carry to kill a person via skin contact?

Question

I'm am developing a creature, what I want to create is a giant octopus that is able to utilize poison. I would like it to shoot it from its beak if the poison is in liquid form, or emit the poison through pores on its skin in a gaseous state.

I have no specific method in mind for the poison to kill, just that it should be able to kill when it comes into contact with human skin, [Its absorbed by the skin into the body] and can kill in less than 20 minutes.

How can the octopus survive the poison, with it being fatal to humans?

Answer 1

The greater blue ringed octopus already has a potent neurotoxin which can be fatal to humans. The octopus has the poison in its saliva, but it is also held in the skin of the mantle, so touching it is potentially fatal.

Answer 2

A jellyfish, sea wasp has the potent poison to kill a human within minutes. It uses tiny darts. Your octopus can have the same method of poison delivery.

Answer 3

Virtually any chemical mixed with DMSO will absorb through the skin. Plus there are a lot of things that are already contact poisons. Wolfsbane for example has such a potent paralytic agent in its sap that merely picking it can be fatal. And if you don't worry about the details too much, anything that comes into contact with the eyes, nose, or mouth will do, or any abrasion of the skin. Spitting cobras target the eyes for example, and their venom will cause temporary blindness. There are a number of books written specifically to be mystery writers' quick-references to poisons that would help you pick what you are looking for by way of potency and effect.

How the creature will survive the poison itself is a slightly more complicated subject, but the basics come down to two methods: Isolation and Immunity.

Isolation means that the creature simply doesn't expose itself to the poison. Such creatures keep their stock of toxic chemicals in specific glands or physical structures, separated from the rest of the body by thick membranes. Among animal life, it's not uncommon for injected poisons to be harmless when eaten. (And sometimes vice-versa. A number of toxic compounds are actually activated by stomach acid.)

Immunity means that the poisonous creature's body either recognizes and breaks down the toxin before it can do any damage, or simply works differently to the point where it has no effect. Jellyfish are unaffected by the neurotoxins they carry because they have no nervous system to speak of. Birds are immune to ingested cyanide because their digestive and respiratory systems are better segregated from each other. If your octopus has copper-based blood, and its toxin affects iron haemoglobin, then it will be unaffected. Or if its nervous system uses different signalling chemicals than a mammal's do, a poison that stops one might have no effect on the other. Monitor lizards have potent bacterial cultures on their teeth that are virulent enough to kill mammals within a few minutes, but to which the lizards are immune themselves; a similar setup with a creature that spits could be quite effective.

Hopefully that's enough ideas to get you on the right track. Remember, you don't necessarily have to explain it in depth unless it becomes a major plot point.

Answer 4

The batrachotoxins can be absorbed through human skin and are among "the most potent alkaloids known".

Answer 5

Your creature could use Fluorhydric acid as a poison. That acid can go through your skin quite easily, sometimes even before you can feel the acid is burning it. When inside your body, it will react with the calcium in your blood, and can cause a heart attack. All that just by contact.

How your creature could survive it is another question I can't answer, but there are several organism that can resist to things that would kill humans such as very high/low temperature, cyanide, radiation etc.... so youe creature could probably do so with acid.

Answer 6

Pretty much any kind of poison you want. How the toxic octopus survives is really quite simple on any of the several avenues that you can take. Neurotoxin, haemotoxin, cytotoxin, targets an organ, etc, really, the choice is yours. It depends largely upon the action of the poison.

Immunity boils down to:

1. the cellular or molecular structure of the thing to be or not be poisoned,
2. the metabolism of the thing to be or not be poisoned,
3. and the structure of the poison.

Examples of immunity or lack thereof:

1. Chocolate is poisonous to dogs.
2. Aspirin is poisonous to cats.
3. Birds can't taste capsaicin (in hot chillis).
4. Fleat treatments don't kill pets if applied properly.
5. Stomach acid (normally) doesn't cause damage to the animal containing that stomach

In the first two cases the animals lack enzymes to break down one or more chemicals which then travel to and damage organs (largely the kidneys). In large doses humans will suffer damage too but in typical doses our bodies can metabolise the chemicals before this happens. In the third, there is no cell in a bird that the capsaicin can bind to, but in humans we can easily and painfully sense it in our mouths, noses, eyes and anuses. The fourth is similar, mammal nerve cells aren't the right shape to be as badly affected as insects. The last is due to a protective stucture, notably a neutralizing mucus.

Neurotoxins produced by animals are proteins, since animals are good at producing proteins, though plants and bacteria produce them too and there are nerve poisons that aren't proteins. Typically they act by binding to nerve cells.

Nerve cells in one type of animal are often different to those in another type of animal. Cobra venom can't poison cobras because on a molecular scale cobra nerve cells are simply the wrong shape to be poisoned. The cobra nerve cell receptor is the same shape as in mammals but nearby the cobra has some other atoms that the big venom molecule can't fit past. Animal flea treatments are neurotoxins but insect nerve cells are different to mammal nerve cells. Your dog isn't killed by having flea poison dropped onto the back of his neck because he, like you, is much less sensitive to the poison than are insects but if he got all that in his mouth it would be dangerous.

Poison dart frogs eat, what is to us and most of their predators, deadly poisons. But their nerve cells are simply not the right structure to be affected and the frogs accumulate this poison to deter predation.

Similarly, many herbicides have no notable effect on animals but others do, like, Agent Orange. The cell structure of animals and plants are different.

If you wanted, the toxic agent could result from a breakdown of one chemical into others. Chemical A isn't poisonous to octopus but in humans it breaks down over time into chemicals B and C, one of which is toxic. Just throw on a cyanide group (they're common) that is released when it's metabolised.

Haemotoxins work by an enzyme (often several) attacking proteins, proteins being a huge part of the human body (and all animals). Snakes, such as most vipers, produce haemotoxins that lead to loss of blood clotting, destruction of tissue around the wound (necrosis), a lot of pain, dissolution of internal organs. These venoms need to enter the bloodstream or otherwise make it into the internal organs. Skin, hair and nails simply aren't affected, or are affected only slowly, even through they are made of proteins. When a snake eats another snake, any poison organ is eaten intact and any haemotoxin is destroyed during digestion.

To avoid these effects the toxic creature would have to produce a neutralizing agent (and some snakes have been observed to produce antivenom), isolate it (with resistant cells), or simply not contain a protein that could be affected by the enzymes (the enzyme can't attack that shape of protein). For example, the enzymes in snake venom that destroy tissue protein are also proteins, but the enzymes are shaped to attack other proteins, not themselves.

Chemotherapy is tailored so that the toxins used preferentially kill cancerous cells (well, it preferentially targets dividing cells, healthy or cancerous, but it relies on cancerous cells doing that more often).