By Mark Brown, Wired UK

This minuscule water boatman might be smaller than a drawing pin, but it's also the loudest animal on the planet. Well, relative to its body size, at least.

[partner id="wireduk" align="right"]The male lesser water boatman, aka Micronecta scholtzi, can create mating calls as loud as 99.2 decibels, which is the equivalent of sitting in the front row of a loud, full-blown orchestra, or standing 15 meters away from a hurtling freight train.

"Remarkably," said Stratchclyde University's James Windmill in a press release, "even though 99 percent of sound is lost when transferring from water to air, the song is so loud that a person walking along the bank can actually hear these tiny creatures singing from the bottom of the river."

To make this colossal acoustic din, the male water boatman rubs his penis (or "genitalia appendage") against the ridged surface of his abdomen, like a wooden spoon against a washboard. Size doesn't matter for this tiny marine animal, though, as the whole area measures about 50 micrometers across – roughly the width of a human hair.

The act of rubbing two body parts together to make a noise is called stridulation, and is seen in insects from grasshoppers to spiders. The only known mammal to stridulate is the streaked tenrec, a spiky hedgehog-like critter from Madagascar that rubs its quills together.

Windmill and his team looked at lots of marine and terrestrial creatures and measured their different auditory outbursts in "acoustic pressure" to find out how loud animals are in relation to their body size.

So while an African elephant's rumbling call can be 117 decibels, if the trunked beast was reduced to the size of a water boatman, the marine insect would far outclass it. As would, it turns out, a snapping shrimp, a speckled bush cricket, a bronze dainty frog, an alligator and a human.

Image: Piet Spaans/Wikipedia

Source: Wired.co.uk

See Also: