Cool Critter: Peters’ Elephantnose Fish
Peters’ Elephantnose Fish. It sounds like a toddler’s creation—as in, “There goes Peter, drawing elephantnose fish again”—but it’s not. It’s a real fish. (And for the record, it’s Peters’ Elephantnose Fish, not Peter’s Elephantnose Fish…we have no idea who Peters is.)
The Central African freshwater fish is about 6 inches long and looks like it’s smoking a stogie. It’s not. The stogie-like protrusion is what Peters called an elephantnose even though it’s not a nose at all and actually extends from the fish’s chin. (With all due respect to Peters, he or she may not have been the brightest crayon in the box.)
Funny looks and a funny name do not earn an animal cool critter status. The critter has to do something cool. And this fish does. It produces electricity and then uses that “elephantnose” to “see” the objects around it. Here’s how it works: Somewhere in the fish’s tail, there’s a source of electricity that produces electrical pulses 80 times per second, creating an electrical field around the fish. Any objects within the fish’s electrical bubble will distort the field. To “see” its surroundings, the elephantnose fish just needs to identify any electrical interruptions.
That’s where the “elephantnose” comes in handy. The fish’s overgrown chin contains more than 500 electrical sensors. And so, by sweeping its trunk from side to side like a metal detector a few millimeters above the gravel bottom, Peters’ fish can detect anything that messes with its personal force field.
But that’s not all. Peters’ Elephantnose Fish has a huge brain (relative to body size, the brain of the Elephantnose Fish is bigger than that of a human). A critter with a brain that big is bound to have a discriminating pallet and for this nocturnal fish, it doesn’t get much better than dead nematocera (i.e. fly) larvae. Luckily, its fancy-dancy electrical system can help it distinguish between things that are alive and things that are dead—and things that have never been alive (like metal). Because living plants and animals can store electrical charges and dead plants and animals cannot, dead organisms “look” different from living organisms to the Elephantnose Fish. (Metal is uber conductive so the electrical image of a metal object is much brighter than the image of a plant or animal.)
That big brain (wrapped in a funny-looking package) also helps the fish measure the distance to an object and an object’s volume. An Elephantnose Fish uses the degree of blurriness of an electrical image to determine the distance to an object, within a few millimeters. And, scientists say, the fish can measure volume, or at least identify the more voluminous of two objects. They have no idea how the fish do this.