Biologist says eels are more sophisticated than a simple shock and kill predator.
A Vanderbilt biologist says electric eels have been viewed as unsophisticated and primitive, but he thinks the creatures are more cunning than they appear to be, according to a report on upi.com.
Kenneth Catania said in a statement his latest research shows that electric eels use their energy charge in a number of ways, and not just for stunning their prey. When tackling a larger prey, like a large crayfish, the eel will curl its body around so its tail is nearer to its mouth. This maneuver brings the two poles of the eel’s charge closer together, and doubles the electric charge sent through the prey in its mouth.
The electric charge from the eel works on the nerves controlling the prey’s muscles, overworking them to exhaustion, and leaving the prey virtually helpless in only a matter of a few seconds.
“The prey animals are completely paralyzed. The effect is comparable to administering a dose of a paralytic agent like curare,” said Catania.
But shocking prey into submission is not the only use for the eel’s electric charge. Catania found that the eels use electricity to scout and track their prey through the murky waters of the Amazon. Making up for the poor eyesight, eels send pulses of electric charges, known as doublets or triplets, while hunting prey. These pulses strike potential meals and cause them to convulse in the water. Eels have sensors in their heads that sense the movement.
After detection of the prey, the eel sends out an high-voltage discharge that allows them to track their prey as it tries to avoid becoming dinner. Feedback to the eel shows the trajectory of the escaping prey and allows the eel to follow.
“One of the eel’s major problems is finding prey in the first place, Catania explained in a press release. “Their environment in the Amazon is filled with muddy water and all kinds of vegetation that give fish a lot of places to hide. So, as the eel glides along, it emits a doublet or triplet. If there is a fish hiding nearby, then its body will spasm and the spasm will generate pressure waves in the water. Although the electric eels can’t see very well, they are very good at detecting water movement. So this reveals the position of its next meal.”
Catania adds, “This dual use of the high-voltage system as both a weapon and a sensory system indicates that the eels’ hunting behavior is far more sophisticated than we have thought.”
Catania’s findings were published in the journal Current Biology.