do you remember the electric eel that jumped out of the water? When electric eels encounter threats that are large and only partially submerged, they protect themselves in this way: jump out of the water, stick to each other and give an electric shock. This dramatic behavior was confirmed by biologist Kenneth Catania. At that time, he used a prosthetic hand with a led lamp to record the electric shock behavior of the electric eel:

(previous introduction: dynamic picture appreciation: electric eel's water strike! )

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this picture makes people wonder: what happens if your arm is really electrocuted by an electric eel?

in fact, the researchers themselves are probably the most curious about this. There are many differences between the artificial hand model and the real person in terms of conductive parameters, and only theoretical calculation may not be accurate, so what should we do? So-- he decided to try it himself!

Yes, this time Kenneth Catania gave his arm for scientific research. He personally experienced an electric shock from the eel and turned the results into a new paper, published last month in Current Biology.

Let's first take a look at the electric shock recorded by high-speed photography (where the picture turns red is the measured discharge time):

his hand is placed in a small plastic container filled with water and metal tape, so that while retaining the human hand and water contact surface, it is also convenient to use copper wire to derive the current for measurement.

the plan seemed pretty crazy, but Catania carefully controlled the risk: "for obvious reasons", he chose only a small electric eel (40cm long, 198V) with relatively low EMF.

what is the result? First of all, it must be quite painful. The researchers said the shock "effectively activated my pain receptors." Although it can't be seen in the high-speed photography of 1000 frames per second above, the sudden pain made him withdraw his hand quickly, just like we did when we were suddenly burned.

measurements show that the peak current passing through his arm is about 43mA, and the frequency of the shock is about 175Hz. During the shock, Catania's arm did not experience significant muscle spasms out of control, but based on the available data, this is entirely possible in larger, more electric eels. They can be more powerful than a stun gun. It seems that this is very effective as a defense for electric eels.

(various parameters in the experiment)

so, is it possible for electric eels to electrocute people? Catania said he had not seen any record of direct death caused by electric shock from an electric eel. But electric eels can be deadly: after all, their electric shocks can cause muscle loss, which can easily lead to drowning in the water. As early as 1807, natural scientist Alexander von Humboldt (Alexander von Humboldt) wrote about horses falling and drowning after being attacked by electric eels.

by the way, Kenneth Catania is really a very interesting person. He has done a lot of amazing research, in addition to the electric eel, but also studied how the star-nosed mole catches odors underwater.

and best of all, he is the only author of all his papers:

kneel to _ (: kneel "∠) _

refer to:

http://www.cell.com/current-biology/abstract/S0960-9822(17)31072-2

https://www.nytimes.com/2017/09/14/science/electric-eels-shock.html