Shrimpoluminescence is, oddly, just what it sounds like. It’s the process by which shrimp create light. This is not just any kind of light though — these shrimp produce light in a unique way. (Ok, you folks who are gleefully imagining sci-fi shrimp with lasers, calm down. It’s not that crazy.)
These shrimp create light by making bubbles.
Alright, that’s a lot to digest. This is the first you’ve heard of shrimp producing light, and now I’m telling you that bubbles can also produce light? Let’s back up a step.
The word “shrimpoluminescence” is a callback to a similar scientific term — “sonoluminescence.” Sonoluminescence is an effect that occurs when small bubbles in a liquid are exposed to intense sound waves. These sound waves compress the bubble rapidly, and with each oscillation, the bubble emits a flash of light, which is bright enough to be seen with the naked eye.
Scientists don’t entirely agree on what’s happening inside the bubble, but the most likely explanation is that the violent implosion of the bubble intensely compresses the gas inside, perhaps setting up a shock wave, which heats the gas inside the bubble to extremely high temperatures — high enough to generate light. In fact, the inside of the bubble reaches temperatures of thousands of Kelvin, or perhaps even tens of thousands! That’s a hot bubble!
So, what does this have to do with shrimp? A certain kind of shrimp, called snapping shrimp, have a tendency to snap their single giant claw with wild abandon when hunting prey or communicating with other shrimp. Their claws make a loud noise and release a powerful jet of water, which can stun small fish. In fact, the shrimp are so loud that they can disturb underwater communication between submarines!
Scientists at first thought that the sound was made when the two sides of the claw hit together, but they later discovered that in fact the sound came from a collapsing bubble, which forms due to the low pressure caused by the water jet. Scientists, because they are a curious lot, noticed the similarities between the two phenomena and decided to look for light — and they found it! A brief flash of light is emitted by the bubble as it collapses.
This was the first example of an animal making light in this way. (It has since been discovered that the mantis shrimp can achieve similar flashy feats.) However, the light is presumably just a curiosity, as it’s short-lived and not bright enough to be seen without scientific equipment.
Read more about the phenomenon here and here.