Sharks have a remarkable gel in their snouts that produces electricity in response to minute temperature changes, enabling the fish to spot heat differences in water that could lead them to prey, a scientist says.

The gel lies in long channels, about 10 centimetres (four inches long), beneath the shark’s skin, which connect pores on the surface with sensors called ampullae of Lorenzini.

These sensors are already known to be highly sensitive to electrical fields generated in the water by the muscles of a wriggling or wounded fish, perhaps even the heartbeat of a swimmer. More here.