What is louder than a blue whale but smaller than a match box?

Jess Moon

It sounds like a riddle, doesn’t it? I promise you though, we’re not looking for a trick answer here. There is indeed a creature that can make a noise louder than the call of a blue whale, but that’s small enough to fit inside the average matchbox. That creature is one of my personal favourites too: the snapping shrimp.

What a racket!

While blue whales can reach 188 decibels with their calls, snapping shrimp just beat them by making a whopping 200 decibels themselves. But they don’t make that sound with their mouths, and they don’t even use it to communicate. Instead, they actually make it with their claws, in a clever method to hunt their prey and scare off predators.

Snapping shrimp have one small claw and one big one that they can flick very quickly, in a similar mechanism to how a pistol would fire a bullet. This creates a bubble in front of them that collapses in on itself due to changes in pressure, and the popping of that bubble is what creates the loud sound. Not only does it make a noise louder than a blue whale’s cry, the energy that is released also produces enough heat to reach almost the temperature of the surface of the sun, and a very brief flash of light that disappears too quickly for human eyes to pick up. These outcomes together can both stun or kill their prey and scare off predators, making it a very effective little weapon for the shrimp to have.

Stiff Competition

The snapping shrimp loses out on being the loudest creature not only in the ocean but in the world to one particular species of whale. The sperm whale can produce clicks that have been measured at 230 decibels – so not all that much louder than the noise that the shrimp can make. That’s doubly impressive when you think that sperm whales are sixteen metres long, while a snapping shrimp is only two inches!

If you’re thinking about keeping a snapping shrimp for a pet though, I wouldn’t recommend it. While they are small enough to keep in an ordinary fish tank, their snap is so powerful that it can crack aquarium glass, so they may need specially made enclosures to stop them from breaking out. Otherwise though, they can apparently be quite good pets!

Things are heating up

Scientists have recently discovered that increasing ocean temperatures might be making these creatures even noisier! A group of biologists in Massachusetts did an experiment where they put snapping shrimps in different temperatures of water and measured how much they snapped. According to their research, the warmer the water, the more they snapped, and so the more noise they made overall. With ocean temperatures rising because of climate change, the cacophony made by colonies of these shrimps might start to be a bit of a problem. It could interrupt sonar for ships, as well as echolocation for animals like whales and dolphins, and just the general lives of some fish.

So, the next time somebody asks you what’s louder than a blue whale but smaller than a matchbox, you’ll know what to say! I’m sure that comes up in conversation all the time…