Question

Explain the mechanism that electric fish use to produce electric organ discharges (EODs). Based on this explanation, why would a fish that uses EODs for hunting and defense be likely to be longer than one that uses electrical discharges solely for communication?

Answer 1

The electric fish is a fish which is able to generate electric fields and it is produced by a specialised structure called as electric organ. It produces electrocytes which leads to movement of ions or electrically charged atoms across the cell membrane which results in electric discharge. The electrocytes receives signals from the brain to fire and at that moment the electrocytes are asymmetrically polarised. The sudden firing of the electrocytes leads to electric organ discharge also known as EODs. The EODs are of two types which are pulse type and wave type.

Most of the electric fishes use this for electrolocation i.e they produce the electric discharged to weaken the predators. It lasts for longer time because the electric field that is created around the fish is very small and it may even be distorted by different objects. There might be electrical resistance and hence it takes more time. The communication is two sided when own discharge of an electric fish is able to detect discharges of other fish.