Electric Stingrays have an ability where they can create an electric discharge for defense. The voltage ranges from specie to specie, but the range is anywhere from 8 volts up to 220 volts. The electric discharge is used in order to stun their prey and can also be used for defense.
There are 69 species that make up 4 families of this type of stingray. The most commonly documented ray of this genus is called the Torpedo Ray. Is has the capability of producing an electric discharge of ~50 volts. Watch the video below to see this ability in action against a scuba diver’s camera who accidentally put this ray in defense mode.
The volts are discharged from 2 organs that are located on the under side of the ray on either side of the bodies as pictured below.
So how does this super cool species produce their electric discharge? Their electric organs are made up of electrocytes. These are muscle or nerve cells that generate electricity. When the ray feels threatened or is hunting, the electrocytes use transmitter proteins to move positive sodium and potassium ions out of the cells which build up the electric charge.
Depending on how many of these cells the ray has determines their maximum voltage capability. Once charged, the ray can then discharge the voltage amount that it is capable of.
So just how strong are these electric discharges? For comparison, 500 volts is enough to stun an adult human. As I mentioned above, the Torpedo Ray can produce an electric discharge of ~50 volts. Watch the effect that it has on this unsuspecting scuba diver:
Nothing too crazy happens, but the scuba diver definitely stops petting the curious Torpedo Ray. In researching for this article I found several videos on YouTube of other people trying to handle this species. It did not go well for them to say the least. I don’t want to give them more attention for harassing marine life so I am not going to include those videos in this article. The scuba diver in the video above was approached by the Torpedo Ray and so he gently reached out to pet it.
The Torpedo Ray did not appear to act as if it was threatened. So the discharge may have been the ray messing with the diver or it got a bit spooked. Either way, if you are fortunate enough to encounter one these awesome rays in the wild, be respectful of their space and always leave them a very obvious exit in case they feel threatened and want to leave the area.
Also keep in mind that our electronics give off an electric discharge. So although it is nothing even close to theirs, the ray may have been slightly threatened by the scuba diver’s electronics from their dive computers and camera equipment.