Sense
Magnetoception (or magnetoreception) is the ability to detect the direction one is facing based on the Earth's magnetic field. Directional awareness is most commonly observed in birds, which rely on their magnetic sense to navigate during migration. It has also been observed in insects such as bees. Cattle make use of magnetoception to align themselves in a north-south direction. Magnetotactic bacteria build miniature magnets inside themselves and use them to determine their orientation relative to the Earth's magnetic field.
Vision in fishes
Cartilaginous fish (sharks, stingrays and chimaeras) use magnetoception. They possess special electroreceptors called the "ampullae of Lorenzini" which detect a slight variation in electric potential. These receptors, located along the mouth and nose of the fish, operate according to the principle that a time-varying magnetic field moving through a conductor induces an electric potential across the ends of the conductor. The ampullae may also allow the fish to detect changes in water temperature.