Is there any biological way an organism can actually breath fire?

I’ve seen countless movies, and read books where dragons can blow fire, and tonight watched Percy Jackson’s movie where the Hydra blows fire.

Mythology aside, is there any biological possibilty a creature could actually breathe fire as an attack/defense mechanism? The closest I can think of to any sort of “fire” are lightning bugs, and eels with electrical charges. I know octopii can eject “ink”, skunks blinding piss, and there’s spitting cobras. But fire? A whole different matter altogether.

There was a special on it on one of those educational channels. It involved having the dragon eat platinum.

I suppose it might be theoretically possible for an organism to simultaneously expel and ignite a flammable gas. The bombardier beetle does something like it. Nothing could literally “breathe” fire, though, since fire isn’t a gas.

Or a liquid spray; something with really high alcohol content perhaps?

Take the mechanism from a bombardier beetle Bombardier beetle - Wikipedia

Add some sort of ignition source… perhaps pressure… something like pistol crabs use…http://www.articlesextra.com/pistol-crab-alpheus.htm (works for diesel engines and compression fire-starters). Or electricity from any electricity producing animal.

Throw in an oil gland to increase flammability of the liquid… or just pipe methane from the intestinal tract.
And bingo, you’ve got yourself a flamethrower.

Off to spice some DNA now? Btw, if you make it work… I want one.

I’m wondering how effective this would be really. A few seconds of flame is not all that harmful unless it is very hot. Even if it’s technically possible for a living creature to develop flame, I find it difficult to imagine that one would produce more than a few seconds of flame or flame that’s all that hot. Plus the animal may set fire to it’s habitation, which isn’t all that conductive to survival.

There are contexts in which it could be useful - in the case of the bombardier beetle, the effect is only momentary, but it makes predators instantly lose interest and go away - so as that kind of a defence mechanism, it would work.

Previous thread, same topic.
As for fire ‘breathing’ itself, I think a two step process along the following lines is plausible:

STEP 1: The development of a workable flame weapon.

*) A creature spits to defend itself. There are already plenty of creatures that already do this, from snakes to camels.

*) The spit becomes increasingly noxious by the addition of volatiles: ketones, alcohols, terpenes. Once again, the addition of noxious volatiles to defensive body secretions is widespread, from skunks to bombadier beetles.

*) At some stage the addition of volatiles produces a flammable mixture. Not a huge leap.

*) The addition of acids from the stomach produces an exothermic reaction capable of igniting the mix. Such reactions aren’t instantaneous, but if you pour a strong concentrated acid onto a wad of grass or paper it can combust within seconds. Since the stomach is already handy to the mouth and already produces a nicely noxious acid this step would seem almost too obvious NOT to evolve.

*) Our animal now has the equivalent of naplam in it’s armoury: a wad of sticky, flammable material that bursts into flame a few seconds after it leaves the animal’s mouth.

All the steps so far are easy to produce by simple evolutionary development. Far simpler than what we see with the bomabadier beetle. And we now have a camel that spits napalm. From that point we have a workable basis for developing classical fire breathing.

STEP 2: The development of true fire breathing

  • We have a mechanism that will promote the evolution of heat-proofing the mouth (to protect from occasional premature ignition).

*We have a basis for the evolution of the ignition system (the napalm system is more effective if there is no delay while waiting for a chemical ignition). Something as simple as a row of hairs could provide a static spark that could ignite volatiles.

  • We have workable basis for the development of specific flammable fuels. Alcohol would be a good choice since it is already genetically available to all tetrapods due to the enzymes that metablise alcohol catalysing reversible reactions.

*We have a workable basis for development of a flammables production system. The salivary glands in ruminants like camels have already been modified to store and secerete nitrogenous wastes, and the glands in various reptiles store and secrete numerous non-salivary enzymes as venom. It’s a plausible step to develop glands to store and secrete alcohol.

  • By increasing the size of the salivary glands we now have a workable fuel storage systems.

At this point we can actually discard the precursor system of producing napalm. Our animal can spray alcohol directly at a target and then ignite the stream mid burst. The alcohol will immediately vapourise and hey presto:

WE HAVE ACHIEVED FIRE BREATHING.

Well actually we have achieved a primitive flame thrower, but the practical distinction between this and fire breathing is non-existent.

I do recall reading an – apparently serious – theory that in some cases, pressure conditions during a dinosaur fart might have been extreme enough to ignite the mixture; of course, I can’t find anything online to cite right now.

However, even if that’s not a viable method, it’s certainly the case that a lot of animals already produce flammable gasses, it would be a rather simple measure of re-routing them and providing an ignition spark (plus some fireproofing perhaps) to produce fire breath. I’m not sure how effective this would be as an actual offensive/defensive mechanism, as presumably all you’d get would be a hot, but short and rather insubstantial combustion. Perhaps the visual would suffice as a deterrent, but in general, some sort of burning liquid would perhaps be the way to go.

Actually, we don’t. We put the ignition organ outside the mouth. I give you the nose! The nose can already secrete, so if it could secrete the igniter, all the creature has to do is spit through the mouth and exhale through the nose at the same time. The two components are kept entirely separate until required so there’s no danger of a premature ignition.

I think you should red my post again.

Well, it’s from the other end, but otherwise qualifies: [NSFW hidden link: 1:30 mark]

Tho you would need a spark of some sort of course.