Natures wonders: electric eels jump out of water (Introduction)

by David Turell , Tuesday, June 07, 2016, 14:34 (3089 days ago) @ David Turell

They can jump out of water to give a Taser-like jolt: - http://www.nytimes.com/2016/06/07/science/like-a-slimy-taser-electric-eels-can-leap-out... - "In 2014, he reported on how the eels freeze their prey. They use rapid pulses of more than 600 volts generated by modified muscle cells and sent through the water. These volleys of shocks cause the muscles of prey to tense at once, stopping all movement. The eels' bodies function like Tasers, Dr. Catania wrote. - *** - "But they can also project high-voltage pulses in the water in isolated couplets rather than full volleys for a different effect. The pairs of shocks don't freeze the prey, but cause their bodies to twitch. That movement reveals the prey's location, and then the eels send out a rapid volley to immobilize then swallow it. - "Dr. Catania noticed another kind of behavior, however. He was using a metal-handled net — wearing rubber gloves — while working with eels in an aquarium, and the eels would fling themselves up the handle of the net, pressing themselves to the metal and generating rapid electric shocks. - "This reminded him of von Humboldt's tale, and he ran some experiments. A partly submerged metal rod, like the leg of a horse in the water, or a metal-handled net, or a hand in the water, can act as a conductor. - "The eels attacked all of the above, pressing what you could generously call their chins against the invader, much as Humboldt described them doing with horses. - "Except that they actually climbed up the offending limb or rod, raising their bodies almost completely out of the water, behavior not included in Humboldt's description. - *** - "He thinks that the leaping, high-voltage attack probably is defensive, and has nothing to do with hunting. The eels eat what they can swallow whole, and do not bite or chew. So, they couldn't eat the kind of large mammal that might be willing to risk a shock from the eels to hunt them. - "The eels' usual hunting method of electrifying the water around them works if the prey is completely submerged. But if a land animal that was hunting the eels put only a paw in the water, it might be able to tolerate the electricity." - Comment: One wonders how the eels developed this electrical power. This is a demonstration of inventiveness or complexification in evolution. Life uses ions which create electrical charges that can run along nerves with great speed, but how does this concentration of power happen?