Electroorientation

Electroorientation is the ability of certain aquatic animals to detect and interpret electric fields. This sensory modality allows these animals to navigate, find prey, and avoid predators in their environment, particularly in murky water where vision is limited. The electric fields can be generated by the animal itself, in the case of electrogeneration, or passively detected from the biological activity of other organisms.

The primary organs involved in electroorientation are electroreceptors. These specialized sensory cells are found in ampullae or pores on the surface of the animal's body, often concentrated around the head and snout. There are two main types of electroreceptors: ampullary electroreceptors and tuberous electroreceptors. Ampullary receptors are typically sensitive to low-frequency electric fields, often those generated by muscle contractions of prey. Tuberous receptors are more sensitive to high-frequency electric fields and are commonly found in weakly electric fish that generate their own electric fields for communication and navigation.

Electroorientation plays a crucial role in the life of many fish species, including sharks, rays, and a variety of freshwater fish. Sharks, for instance, use their ampullae of Lorenzini to detect the weak electric fields produced by the muscle movements of hidden prey. Weakly electric fish, such as some species of knifefish and elephantfish, use their electrogenic organs to create their own electric fields. They then sense distortions in this field caused by objects or other living beings, providing them with a detailed "electric image" of their surroundings. This allows for effective foraging, social signaling, and spatial awareness even in complete darkness or turbid waters.