Sharks have existed for over 450 million years, making them older than dinosaurs. These apex predators are found in every ocean, from surface waters to the deepest trenches. Most sharks are carnivorous and use electroreception to detect prey through electrical signals. Unlike most fish, shark skeletons are made of cartilage rather than bone, making them incredibly flexible and agile hunters. Sharks play a crucial role in maintaining ocean ecosystems by controlling fish populations and keeping marine environments balanced.