Electric Rays Profile
A surprising number of animals can produce electricity as well as receive it. Catfish might be some of the most surprising, but stargazers, skates, and the infamous electric eel are other examples.
Electric rays sound like the psychedelic weapon of a certain light orchestra from the ‘70s but they’ve actually been around even longer than ELO, having been recorded by Pliny and Aristotle, and of course, evolving long before the earliest human civilisations.
Their powers have not gone unnoticed, and may even have paved the way for our understanding of how electricity affects the human body.
Electric Rays Facts Overview
| Habitat: | Shallow coastal waters down to at least 1,000 m |
| Location: | Worldwide |
| Lifespan: | 24 years or more |
| Size: | Up to 2m (6 ft) long |
| Weight: | Up to 90 kg (198 lb) |
| Colour: | Varied, from black to orange, speckled, marbled |
| Diet: | Fishes and invertebrates |
| Predators: | Some sharks, other large cartilaginous fishes |
| Top Speed: | Slow |
| No. of Species: | 69 |
| Conservation Status: | Least concern to Vulnerable (IUCN) |
Electric rays are a small but diverse group of rays from one of the four orders within the superorder Batoidea. These are all known for their wide, wing-like fins and their flat appearance, and electric rays don’t disappoint in that regard, but they also come with a little extra.
Known for thousands of years for their “magical” properties, these rays are outstanding among marine fish for the sheer amount of power they can produce.
Interesting Electric Rays Facts
1. They’re Torpediniformes
The rays come in four orders: the enormous devil rays are the Myliobatiformes, the infamous stingrays and skates are Rajiformes, the triangular-faced shovelnoses are Rhinoprisitformes, and older than each of these is the earliest order, Torpediniformes.
Within this order are three families of electric rays, each more frighteningly-named than the last. There are the Torpedo rays: Torpedinidae; the numbfishes: Narcinidae, and the coffin rays: Hypnidae.
If some of these rankings remind you of the infamous submarine missiles, that’s no coincidence.
The Latin word torpor means numbness, paralysis, or low energy, and is used to describe a state of hibernation, as well as the stiffness associated with the phallic explosive that pops out the end of a submarine when it gets excited by an enemy boat.
The fish, who don’t hibernate and look more pancake-shaped than phallic, acquired the name on account of the numbness, stiffness or paralysis that can occur among those who get too close to them.
2. They’re not magic
The ability of this animal to inflict numbness on the appendages of those who bother it has given it almost legendary status among human cultures throughout history.
It’s been considered a magical creature, and associated with the occult, and the global distribution of these fish across the various species has allowed people from all over the world to wonder what on earth is going on.
But thanks to science (and Tim Minchin), “every mystery ever solved has turned out to be: not magic”. Including this one. 1
3. They’re biological batteries
The bizarre effect that ancient fishermen picked up on comes from an unusual pair of organs on the sides of the animal’s head.
These are patches of modified muscle cells that generate an electrical gradient that’s concentrated into a tiny spot. The tissues around these organs can store electricity in them just like a battery, and this stored energy can be released in sudden pulses, to alarming effect.
Shocks like this can range up to 220v and are great at making a predator think twice about interacting with the ray, but equally good at stunning a sharp and snappy animal like a crab before swallowing it.
After the release of so much energy, there’s a familiar refractory period while it recuperates and builds back up its electrical potential.
Shocks can occur without physical contact, being conducted through the salty water, and this usually isn’t medically significant to a human but could cause trouble for the weak-hearted or very young. 2
4. This is different from other fish
It’s this salinity that explains the differences in the electric organs of these rays when compared with freshwater fishes like the electric eels.
In freshwater, there are fewer dissolved solutes, and therefore less conductivity for electricity to pass through; in saltwater, the same effect can be achieved at a lower voltage. So, the cells in a freshwater electric fish are wired in series, increasing the voltage – in electric rays, they’re connected in parallel, increasing current.
This is also different from other electric marine fish. Skates, too, have electric organs, but the charge they build up is not strong enough or released in the right way to be used as defence or attack, suggesting that it’s more likely a form of defence.
Unsurprisingly, the power of the shock from electric rays makes them unpopular as a food source, and excellent as a predator.
5. They’re ambush predators
Electric rays spend most of their time buried in the sand. They’re not fast animals, and unlike other rays, they use their chunky tails for propulsion, rather than the elegant rippling of the wide fins we commonly associate with rays.
This is a very low-energy strategy, which allows them to store up high energy in the tissues for use in hunting.
But, while they’re not popular as food, they have been used by various cultures as a remedy for various ailments. 3
6. They’ve been used as medicine
The Greeks used the charge emitted by these rays as an anaesthetic, perhaps similar to a TENS machine, while performing operations and during childbirth.
Roman physicians used them to treat headaches, and even Hippocrates prescribed their use in the context of disease recovery.
Even as late as the 1700s, physicians were using these fish for treating epilepsy, depression and arthritis. 4
Electric Rays Fact-File Summary
Scientific Classification
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Chondrichtyes |
| Order: | Torpediniformes |
| Family: | Narcinidae
Hypnidae Torpedinidae |
Fact Sources & References
- Brian P. Copenhaver (1991), “A Tale of Two Fishes: Magical Objects in Natural History from Antiquity Through the Scientific Revolution”, Journal of the History of Ideas.
- “Electric Ray”, Science Direct.
- “Electric (or Torpedo) Ray (Torpedo nobiliana)”, Uhi Shetland.
- “The Shocking Medical History of Electric Fish”, Longnow.