Elasmobranchs are a subclass of cartilaginous fish that include species such as sharks and rays. They are characterized by their flattened bodies, gills located on the underside, and a lack of bony skeletons, which makes them unique among fish. These fascinating creatures play vital roles in marine ecosystems as predators and scavengers. Elasmobranchs have a keen sense of smell and can detect electrical fields, aiding them in hunting. Their diverse adaptations allow them to thrive in various ocean habitats, from shallow coastal waters to the deep sea.