Bull sharks at night

Bull sharks are more commonly seen in the planet's seas but they also live in freshwater. They can hunt 24 hours a day by using acute senses that allow them to hunt in murky rivers at night. Finding electrical charges given off when prey use their muscles and a superb sense of smell that can detect one part blood per million parts water are key to their success. Sharks also have a lateral line sensitive to motion and can feel a fish swimming near them, a bit like feeling the wave of pressure left as a large truck rushes past you on the road, as Bryson Voirin explains.