In a series I'm writing, there are seven categories of species of intelligent, human-like creatures with magical abilities that vary by species. One of them is a revamp of mermaids, or as I call them, Merpeople.

Merpeople are various aquatic vertibrates(mostly) that don't resemble humans in the slightest, but are just as intelligent. To keep the other intelligent species from eating them, the Merpeople learned to shapeshift into human-looking creatures. All Merpeople have hydrokinesis to a degree, in both forms. Their forms are called Natural/Original form and Artificial(humanlike) form.

The Artificial form of an individual weighs the same amount as their Natural form. The Merperson physically shifts the mass in their body to be bigger and look different, but it's still the same (amount of)substances. Their internal organs are carefully rearranged to fill in the space inside the different rib cage and skull better, and the bones enlongate and change shape to support standing upright(they're known for having weak bones), and they form artificial 'lungs' that are much bigger than ours to absorb more oxygen, inhaling through their mouths.

One of the main characters' Natural form(they're a Merperson)resembles an electric eel, complete with their electrogenesis(a living thing being able to generate electricity) and electroreception(being able to sense other living things/objects via sensing a disturbance in once's own electromagnetic field). In human years, they're about 15 years old. They can't shock people on land the same way that they can underwater while in their Artificial form, but they still have the ability to generate electricity.

I can't figure out how to map the electrical organs onto a humanoid. I have done research on everything from human-knifefish common ancestor(Gnathostomes, that knowledge did not help) to looking at diagrams of the organs to reading several full Wikipedia pages on electric eels and their relatives.

Here's what I need to know:

  • How could a humanoid have electric eel-like electrical organs? Where would they go? How big would they be, and how close together?

  • How would they shock someone? Is physical touch necessary? If not, how far away could they shock someone with the average electrical output of an electric eel?

  • An adult electric eel can generate a range of ~600 to ~800 volts of electricity for about a full minute. No sources said anything about age affecting output. At what age(relatively) can an 'eel produce electricity, and at what increment does the output increase as they get older?

  • How fast do electric eels age in comparison to human years?

And, although I didn't mention this earlier;

  • Since all they do when they shapeshift is rearrange preexisting parts of their body, would they be able to have good eyesight if they wanted to? They can only rearrange at the cellular level, not at the molecular, atomic, or smaller. They wouldn't be able to replicate any sense or ability that requires specific cells that they don't have in their natural form. What other senses do electric eels have, and how good?

I appreciate your help and would love to hear what you have to say.

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    $\begingroup$ So you've never heard of electric eels then? no. no I see that you have, so how do you still have a problem then? huh, you want to know where to put the organ, really, is that really it? .. wherever you want that seems about right .. this is pretty much an opinion question where pretty much any answer is as good as another. $\endgroup$
    – Pelinore
    Commented Apr 5, 2023 at 21:59
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    $\begingroup$ (a) For future reference, you are allowed to ask one and only one question per post. The "Needs More Focus" closure reason is defined as asking more than one question. (b) You really need to read the wiki for the hard-science tag. This is the second time you've used it, and I'm convinced you don't understand what it means. Answers that can't prove themselves true with citations and mathematics are under threat of deletion, and yet you want hard science for a fanciful and fictional creature. The hard-science tag is entirely inappropriate here. $\endgroup$
    – JBH
    Commented Apr 5, 2023 at 23:29
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    $\begingroup$ (c) Further, too many of your questions have nothing at all to do with science (much less hard-science). They're story-based questions - the "right" answer depends on the needs of your story, not science. Please read the Meta post about narrative necessity. $\endgroup$
    – JBH
    Commented Apr 5, 2023 at 23:32
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    $\begingroup$ worldbuilding.stackexchange.com/q/180448/30492 and worldbuilding.stackexchange.com/q/171406/30492 $\endgroup$
    – L.Dutch
    Commented Apr 6, 2023 at 5:00

2 Answers 2


Electricity is any phenomenon associated with stationary or moving electrons, ions, or other charged particles.

If they are magic 🧙, then they can generate a field of positive charge. This will repel the electrons in the air (and attract the protons) into an explosion of electricity. (Might cause radioactive side effects)

Electric eels are actually better out of the water (with contact), so that is not a problem going that rout too.

As for aging, aging is mostly decided by evolution and activity. Any species that has a strong reason to live long (humans, cetaceans, elephants, giant isopods, termite queens etc.) evolves to do so. Any species that doesn't do a whole lot (like crocodiles 🐊, tortoises, giant isopods etc.) tends to just do so due to.


Electric eels are successful because electricity dissipates in the water, so in order to zap someone on dry land they should have a gland that shoots a fluid to the target. While the fluid is in mid air they discharge electricity into the fluid and when the liquid touches the victim the current gets passed on. Basically an electric spit. As for the organ. Electric eels are as long as they are because their electric organ is as long as it is. In my understanding when this merpeople get onto land they shapeshift into a human like form. The easiest solution is to make that organ literally their tail. Another solution is to attach that organ to their head in a way it can resemble hair that can be arranged in different way or even groomed. Heck you could do an electrical Medussa.


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