How do elasmobranchs catch their prey?

The predatory sharks, rays, and skates have highly developed senses that are used to detect and catch their prey.  The primary sense used by sharks and other elasmobranches is hearing.  Sharks can hear a struggling fish from 2 km (3.2 miles) away!  Elasmobranches also have a highly developed sense of smell and excellent eyesight and they can even detect the electrical impulses that are produced by the muscle movements of their prey.  These keen senses have allowed these creatures to thrive in the earth's oceans for millions of years.  The elasmobranches that are filter feeders tend to take water in through gills that have undergone adaptations to ensure that they can filter the water and provide food for the shark or ray.