Shark

A shark is a cartilaginous fish belonging to the subclass Elasmobranchii, a group that also includes rays and skates. Unlike most fish, sharks have skeletons made of cartilage rather than bone, making them lightweight, flexible, and efficient swimmers. They have inhabited Earth's oceans for more than 400 million years, predating the dinosaurs, and today more than 500 species are found in oceans around the world, from shallow coastal waters to the deep sea. Sharks vary greatly in size, ranging from the small dwarf lanternshark, which is only a few inches long, to the whale shark, the largest fish in the world, which can exceed 40 feet (12 meters) in length. They are equipped with multiple rows of continually replacing teeth, an exceptional sense of smell, keen eyesight, and the ability to detect the electrical fields produced by other animals, making them highly effective predators or filter feeders depending on the species. While many sharks hunt fish, seals, squid, and crustaceans, species such as the whale shark and basking shark feed primarily on plankton. Sharks play a vital role in maintaining healthy marine ecosystems by helping regulate ocean food webs, and despite their reputation in popular culture, attacks on humans are extremely rare. Throughout history, sharks have symbolized strength, resilience, and the untamed power of the ocean, making them some of the most fascinating and important animals in the marine world.