The Elephantnose Fish: A Freshwater Fish That Senses With Electricity

Photo: unknown photographer, CC BY-SA 2.0, via Wikimedia Commons

The elephantnose fish gets its name from a long, trunk-like extension at the front of its face. The trunk is not a nose in the usual sense. It is a flexible, mobile chin extension, and the fish uses it like a probe, feeling through the mud for insect larvae and small invertebrates.

Photo: Unknown, CC BY-SA 2.5, via Wikimedia Commons

The real trick is electrical. The fish produces weak electric pulses from an organ in its tail and senses distortions in the field with special receptors on its skin. This lets it detect objects, food and other fish in muddy water where eyesight is not much use. The process is known as electrolocation.

Photo: El SHINDANI, CC0, via Wikimedia Commons

It lives in rivers and streams in West and Central Africa, including the Congo basin, and it is active at night. The brain is large for the size of its body, and much of the brain is devoted to processing the electric sense, which is one reason that scientists study it.

Diagram: Carl Hopkins, CC BY-SA 3.0, via Wikimedia Commons

The species is sometimes kept in aquariums, but it needs a calm tank with soft sand, hiding places and careful feeding. It can be shy, and it can be stressed by bright light and aggressive tank mates.

Photo: Jutta234, CC BY-SA 3.0, via Wikimedia Commons

I find the idea of a fish that sees with electricity wonderful. Have you ever seen one in an aquarium?