Electric fish have developed organs capable of producing an electric field. Some are also called electric fish because they can sense electricity from their surroundings.
Fish are the most diverse vertebrate animals living in fresh and salt water. Among this variety are surprising adaptations, such as some emitting electricity without electrocuting themselves.
What is an Electric fish?
Did you know that electric fish were used as electrotherapy for epilepsy in Ancient Egypt? Keep reading this article, where we present six examples of electric fish, their characteristics, and how they can have this ability.
Animals, including us, have cells through which electricity flows, specifically in sodium channels that function as muscle motors with small amounts of electricity.
Even so, the muscle or neural tissues have been modified in some electric fish to generate electrical discharges. This occurs due to a genetic modification and provides advantages to the fish that have it.
They are mostly found in freshwater, saltwater, and the ocean. Since water is a great medium that conducts electricity, these fish can functionally use their electrical systems. The salts in the water also help conduct discharges better, which is why there are more marine fish with electrical capabilities.
Their electricity can be used to capture prey or defend themselves. Some can interpret the surrounding electricity to find others of their species, engage in courtship rituals, or detect food.
Electric fish can be divided into two groups.
Those that emit electricity.
The electroreceptive ones or those who receive shocks and interpret them. It is estimated that approximately 30% of fish are electroreceptive, and 5% of these can emit electricity. Let’s review some examples.
Black ghost knife fish (Apteronotus albifrons)
This fish cannot only produce electricity but also receive it. It uses a system similar to the echolocation of bats or dolphins. Fish emit electrical pulses that are returned so that the fish can interpret the information received from the change in the waves. This is called electrolocation and is used to detect food or predators.
The tail has an organ that emits electric discharges, and the skin has sensory cells that receive electricity, called electroreceptors. The fish emits high-frequency waves, which are detected by tuberous electroreceptors.
It can also perceive low-frequency waves coming from outside, called passive electroreception. These waves are perceived by the ampullary or Lorenzini organs, which are pores in the skin with mucus inside.
The discharges it emits are not lethal but are only used for locating purposes.
Electric catfish (family Malapteruridae)
An example of an electric fish is part of the Malapteruridae family known as the electric catfish. The organ they use to generate electricity is called an electrolyte or electroplate, deriving their anterior musculature.
They can generate discharges of up to 350 volts, with which they can electrocute their prey. It lives in Africa, and the ancient Egyptians used the smallest ones to treat arthritis.
Electric eel (Electrophorus electricus)
The electric eel is a worm-like creature, and its electric discharges are also lethal. A single eel can discharge 850 volts on its prey, which is emitted by the Hut organ. But in addition to these discharges, it has another organ called the Sachs organ, with which it sends very low discharges, of just 10 volts, used to locate itself within its environment by means of electrolocation.
Electric ray (order Torpediniformes)
These rays, relatives of sharks, have two very large electrical organs on their heads. These are central nerves branched in the shape of a honeycomb. They can emit 220-volt discharges and use them to catch their prey. They live on the sea floor and blend in with it to wait patiently for their food, mainly invertebrates.
African razorfish (Gymnarchus niloticus)
This elongated fish emits low-volt electrical discharges to help it locate itself. Thanks to these electro-locating discharges, it can even swim backward and forward. It uses these discharges not to feed itself but as a sensory aid.
Elephantfish (family Mormyridae)
They have an extension in their mouth that makes them look like elephants. They are also unusual for their electroreceptor capacity, which helps them find food and locate themselves. The water is very murky, and they cannot rely on their vision. They also meet other elephant fish by recognizing their particular electric discharges.
Its brain is particularly large to its body and is even the largest of all fish. It is suggested that this is due to the information it receives through its discharge-receiving organs. Like the knifefish, it also has two types of electrical cells: Lorenzini and tuberous. Both are derived from muscle cells modified to receive and send electrical energy.