Sensing Electricity

Every living body leaks a faint electric field whenever its muscles and nerves fire. Sharks can feel it.

They sense it through ampullae of Lorenzini, gel-filled pores clustered around the snout that pick up fields as weak as a few billionths of a volt. That is among the most sensitive electric sense known in any animal.

It means a shark can find a meal it cannot see, smell, or hear. A flatfish buried under sand in pitch darkness still gives itself away, betrayed by the tiny electrical pulse of its own heartbeat.

Smell in Stereo

Sharks have excellent smell, but the famous 'one drop of blood in a swimming pool from miles away' version is exaggerated. Sensitivity depends on the chemical, dilution, water movement, and shark species.

What sharks do brilliantly is track gradients. By comparing when odor reaches each nostril, they follow a plume through moving water toward its source.