This fungus shoots off spores that accelerate faster than a speeding bullet

Crowning the world's fastest creature is far from a straightforward affair.

Some insects have quickly snapping mandibles that move very short distances faster than the almighty cheetah can sprint - and those are only contenders if we stick to land animals only.

But in terms of acceleration, a few slow-motion wizards at BBC's Earth Unplugged series have captured the spurts of a manure-dwelling fungus called pilobolus.

The organism is ingested via vegetation munched by plant-eaters. From there the spores make their way through the animal's digestive system, and out back into the world, unscathed. Once digested, the fungus grows stalks called hyphae.

The hyphae grow and develop fluid-filled bulbs. These "fungus cannons" fire off spores when the pressure gets too great, propelling them away from the fungus. These spores end up on nearby plants, far enough from the fungus-ridden dung to perpetuate the cycle.

Check out the spiral on this one!

The BBC wanted to know whether piloblus spores accelerate faster than a speeding bullet. To figure that out, they captured the philolobus' "squirt gun mechanism" - as well as an old rifle and a newer shotgun being discharged - in slow motion.

First up was a replica of a Remington Rolling Block, a pretty vintage rifle. To measure the bullet's acceleration, the experiments subtracted the projectile's initial velocity from muzzle velocity before dividing the difference by time elapsed.

They found that the bullet was accelerating at 9,395 g's, or 9,395 times the acceleration of gravity. (One g equals 9.8 meters per second per second, which is how fast an object accelerates in free fall when dropped toward the ground.)

They also had a firearm specialist pull the trigger on a shotgun. It clocked in a slightly lower acceleration of 9,313 g's. Neat how the slow motion shows smoke oozing out of the barrel well before the bullet comes.

Then, in an indoor setting, the pair sought to capture the pilobolus with a camera operating at nearly 22,000 frames per second. They waited more than three hours for the magic moment.

"Their top speed's not that impressive," one of them says. "They've been recorded going about 25 meters per second."

But hey, that's 56 miles an hour - not much slower than what a cheetah reaches at full sprint. And to the naked eye, the spores are so quick that they almost seem to disappear instead of firing off.

Besides, we're looking at acceleration here. And in that domain, pilobolus spores do in fact, ahem, outgun the guns; the spores were found to accelerate at 20,000 g's, more than twice what the rifles achieved.

And if you think 20,000 g's is impressive, the researchers point to a study that cites fungal explosions of more than 180,000 g's (over a distance of 2.5 meters).

Even in the realm of fast-flinging fungi, then, pilobolus isn't the most extreme. But at least we've got it on camera.