Electroreception
From Wikipedia, the free encyclopedia
Electroreception, sometimes written as electroception, is the biological ability to receive and make use of electrical impulses. It is much more common among aquatic creatures, as water is a far superior conductor to air. Electroreception allows for electrolocation, the ability to locate an object by electricity.
Contents |
[edit] Mechanism
Many fish have an electroception sense, believed to be associated with the lateral line system.
There are two main modalities of electroreception. During the "active" electroreception, the animal generates electric fields; the environment produces a distortion of the animal’s fields, detected by the electroreceptor organs. An example of animals that generate their own electric fields are the weakly electric fish (including fish from the groups Gymnotiformes, Gymnarchidae, and Mormyridae).
In the "passive" electroreception, the animal does not generate any electric fields and it senses the electric fields generated in the environment. An example of animals that use the environmental electric fields are sharks and rays.
Both of these methods of electroreceptrion allow for the animal to locate predators or prey, depending on where a distortion of their own electric field or change in the environment's electric field occurs.
[edit] In Elasmobranchs
Electric fields simulating prey in the seawater are sufficient to elicit robust feeding responses, showing that sharks and rays in their final attack heavily rely on their electric sense. The DC electric fields that the sharks respond to are as low as 0.005μV/cm, what makes them the most sensitive animals known today.
Sharks electric sensors are the ampullae of Lorenzini, receptors connected to the seawater by pores on their snouts and other zones of the head which allow them to sense electric fields in the water. A problem with the early submarine telegraph cables was the damage caused by sharks who sensed the electric fields produced by these cables. It is possible that sharks may use Earth's magnetic field to navigate the oceans using this sense.
A recent study has suggested that the same genes that contribute to a shark's sense of electroreception may also be responsible at least in part to the development of facial structures in humans.
[edit] In other organisms
The electric eel, besides its ability to generate high voltage electric shocks, actually uses lower voltage pulses for navigation and sensing prey in the turbid waters in which it lives. Other gymnotiform fish also have the capability.
Monotremes are the only known mammals that possess the ability of electroception. The platypus is known to have the most acute sense.
