Brainiest fish follows its chin, according to an article in news@nature 23 Aug 2007. The elephant nose fish is a weird looking fish with an elongated projection sticking out from its chin. This contains numerous electrical senses than can detect distortions in the fish’s own electric field to help it navigate around obstacles in the dark.

Scientists at the University of Bonn, Germany, have tested the ability of the fish to distinguish different shapes in its environment by placing a cube and a pyramid in its tank and rewarding it with a worm when it swam to the pyramid. After the fish had learned to recognise the pyramid the scientists substituted it with a wire frame in the shape of a pyramid and the fish still picked it out, suggesting that the fish could use its electric sense to form an impression of a shape from just its outline. If the pyramid wasn’t present the fish swam towards the object that was the closest match in volume. Gerhard von der Emde, who led the study, commented: “It’s very impressive how detailed their view of the environment is.”

The elephant nose fish has the biggest brain (relative to body size) of any fish, and these experiments indicate that it can build up “sophisticated three dimensional images of its natural environment” using the electrical sensors. In its natural environment the fish sweeps its “nose” over the ground like a person using a metal detector to find its way around obstacles and find food. The researchers are hoping to copy the “electrolocation” system and develop electric field sensing devices that could be used to give night “vision” to underwater robots.

Editorial Comment: The electric sense of this fish is clearly superior to any man made metal detector and if scientists are able to copy it they will again have proven that it takes creative design and engineering to make such a device. This fish is not the first creature discovered to use electric senses to find its way around in the dark. The “duckbill” of the platypus also contains electric sense organs that enable it to swim along the muddy bottoms of rivers with their eyes closed, avoiding obstacles and finding food. (Ref. Design, biomimetics, bio-engineering)

10th October 2007