Sharks are a diverse group of cartilaginous fish characterized by a streamlined body, multiple gill slits on the sides of their heads, and a range of sharp teeth adapted for their carnivorous diet. They inhabit all the world's oceans, from shallow coastal regions to the deep sea. Sharks play a crucial role in marine ecosystems as apex predators, helping maintain the balance of marine life by controlling the population of other species. There are over 500 known species of sharks, varying greatly in size and behavior, from the small dwarf lanternshark to the massive whale shark. Despite their fearsome reputation, many shark species are threatened by overfishing and habitat loss.
