The Fish That Communicates with Electricity – Nature’s Underwater Morse Code

In the dark and murky waters of rivers and swamps, sight and sound don’t work very well. So how do some fish manage to find food, avoid predators, and even flirt with potential mates in total darkness?

The answer? Electricity.

Meet the weakly electric fish, a fascinating group of creatures that have developed a sixth sense — one that lets them "see" using electric fields and even communicate through electrical signals, like underwater Morse code. This isn’t science fiction. It’s real, living biology, and it’s absolutely wild.

What Are Weakly Electric Fish?

Unlike electric eels that can shock prey or predators with a strong jolt, weakly electric fish produce very low-voltage electric fields — often less than 1 volt. These fields aren’t meant to attack. Instead, they’re used for navigation, object detection, and communication.

There are two major groups of these fish:

• Gymnotiformes – found mainly in South America (e.g., black ghost knifefish, electric eel),

• Mormyridae – found in Africa, often called elephantnose fish due to their long, trunk-like mouths.

How Do They Create Electricity?

These fish have electrocytes — specialized cells in an organ usually located near their tail. These cells work a bit like tiny batteries. When triggered, they release small bursts of electricity in controlled patterns.

Some fish produce continuous waves, while others send short pulses. These electric signals form a kind of radar field around them.

When objects — like rocks, plants, or other animals — enter this field, it disturbs the pattern. The fish senses the disturbance using electroreceptors on its skin and instantly knows something is nearby.

Communication with Electric Signals

Here’s where things get really exciting.

These fish don’t just use electricity to explore their surroundings. They also send messages to each other:

• Courtship: Males and females emit specific frequencies when they’re ready to mate.

• Territorial warnings: A fish may send aggressive bursts to warn others to stay away.

• Social signals: In species like the elephantnose fish, individuals can recognize each other’s electric “voice.”

Each fish has its own unique frequency — like a personal ringtone — so they know who’s around even in complete darkness.

It’s a form of communication that humans can't detect with our senses, but in the electric fish world, it’s as clear as a conversation.

Electric Brains

Studies show that these fish have extra-large brain regions dedicated to processing electric signals — sometimes even larger than the part of the brain that handles vision in other fish.

Some scientists believe this makes them among the smartest of all fish species.

In fact, the elephantnose fish has a brain-to-body ratio comparable to that of birds and mammals, making it a superstar in the underwater IQ club.

Why the Elephant Nose?

The African elephantnose fish has a long, fleshy appendage that looks like a mini trunk. But it’s not a nose — it’s actually an extension of the fish’s mouth.

This "trunk" is packed with electroreceptors and helps the fish locate food buried in the muddy riverbed.

Combined with its electric field sensing, this gives the fish incredible precision in finding prey — even tiny insect larvae hidden under sand.

Inspiration for Technology

Scientists and engineers are studying these electric fish to develop new technologies, including:

• Underwater navigation systems for robots (inspired by electro-location),

• Non-visual sensors for use in dark or murky environments,

• Communication systems for devices that can work without sound or light.

Nature, once again, is ahead of us in innovation.

Final Thought

While most animals rely on eyes and ears, weakly electric fish have mastered a completely different way of sensing and speaking — through electricity. They remind us that life on Earth is full of incredible surprises, and sometimes, the most advanced communication systems come from places we rarely look.

So the next time you think of electricity, don’t just imagine wires or lightning bolts. Think of a quiet, graceful fish gliding through the water, speaking in zaps and pulses — a living whisper in the current.