As most of you probably know, living beings emit heat as form of energy transfer. Even the sweat we emit can be interpreted as energy transfer, but certain fish can actually generate electricity. I know it sounds weird and perhaps even unbelievable if you haven’t heard about it before, but there’s real science behind it.
Electric eels are capable of generating shocks which are so strong they can actually incapacitate and even kill larger predators. If you’ve ever seen or are familiar with Pokemon, you’ll probably be able to relate to what I’m talking about. Except this is real, and not a cartoon with fictional creatures.
So how does it all work then? How can a fish generate high-voltage attacks which can incapacitate another animal? Although the actual process is rather complex, it can be broken down into something so simple everyone can understand. A recent TED-Ed explains the science behind it. You can watch the video at the end, but I’ll try to simplify it for anyone interested in a quick summary.
Electric fish, including electric eels, contain at least one electric organ in their body. This organ features disc-shaped cells also called electrolytes. These cells release sodium and potassium ions naturally, thus creating a positive charge inside of the cells, and a negative one outside. It creates a sort-of static electricity if you will.
When the fish feels threatened or needs to defend itself it sends electric signals from the brain to the organ to open up the cells’ ion channels. This means that the ions are now allowed to re-enter and flow freely. As a result, you get an electrolyte with a positive interior and a negative exterior from one side, and the complete opposite from the other. In essence, it’s a biological battery, because the concept in which most batteries operate these days is exactly the same.
When these cells are fully charged up, the fish can use them to disrupt other signals, detect other fish in the area, and even, as I mentioned, paralyze prey. Because this process takes place underwater, the shock to the nearby area is greater than what it would have been on dry land through the air as a transfer medium.
Fish aren’t the only animals who utilize electricity, however. The oriental hornet can generate electricity from sunlight and certain spiders can harvest already-charged particles from their webs, using electrostatic glue. Nature is as fascinating as it is scary sometimes.