The other shocking organ found in electric eels
If we weren’t still finding live electric eels in the world, their description would sound like some absurd, fictional monster invented by a 10-year-old. They’re not actually eels, but a member of the knifefish family. The serpentine body is mainly a way to house their electric organs which can produce a 600 volt shock to immobilize prey, leaving the rest of their organs to be crushed up into their heads. These organs include a very unusual addition for a fish- a lung, smooshed into the eel’s mouth.
The lining of an electric eel’s (Electrophorus electricus) mouth is a dense collection of cauliflower-shaped nodules, much like the inside of a human lung. As in our lungs, this increases the amount of surface area available to collect oxygen when the eel breaths in. Since the water in the Amazon and Orinoco basins can be so murky, shallow and occasionally stagnant, the eels can only rely on their gills for 20 percent of their oxygen supply. The mouth-lung is then used to make up the difference when the eel surfaces every 10 to 15 minutes. It also makes it safer to travel down small, narrow tributaries with less risk from beaching themselves.
The thick, muddy environment also reinforces the eel’s hunting tactics. Since visual information is unreliable in dark, clouded water, the eels can use their electric organs to send out a variety of electrical pulses. Some can act almost like sonar, helping the eels navigate and locate prey. A stronger, double pulse can then force a potential meal to involuntarily twitch, revealing their otherwise cloaked location. Once they’ve been found, the eel can strike, effectively paralyzing their prey by overwhelming their muscles with electricity. They’ve even been known to use these tactics on land-loving animals near the shore, making further use of their ability to happily be a fish out of water, if only for a bit.
Source: Electric eels have some of the strangest mouths in the animal kingdom by Sarah Keartes, EarthTouch News Network