rekin

Rekins, commonly known as sharks, are a group of elasmobranch fish characterized by a cartilaginous skeleton, five to seven gill slits on the sides of the head, and pectoral fins that are not fused to the body. They are among the oldest living vertebrates, with fossil records dating back over 400 million years. Sharks inhabit a wide range of environments, from the deepest ocean trenches to shallow coastal waters, and are found in all oceans except the polar regions.

Sharks exhibit a diverse array of sizes, shapes, and behaviors. The largest species, the whale shark (*Rhincodon typus*), can reach lengths of up to 12 meters (40 feet) and feeds primarily on plankton. In contrast, the dwarf lanternshark (*Etmopterus perryi*), one of the smallest, grows to just 17–20 centimeters (6.7–7.9 inches). Most sharks are carnivorous, preying on fish, seals, sea lions, squid, crustaceans, and other marine life, though some species have specialized diets, such as the filter-feeding basking shark (*Cetorhinus maximus*).

Sharks play a crucial role in marine ecosystems as apex predators, helping to maintain the balance of marine life by controlling populations of prey species. They are also ecologically significant as keystone species, meaning their presence influences the structure of their environment. Unfortunately, many shark species face threats from overfishing, finning, habitat destruction, and climate change. Conservation efforts, including protected areas, sustainable fishing practices, and international regulations, aim to mitigate these risks and ensure the long-term survival of shark populations.

Culturally, sharks have often been depicted in media as dangerous predators, though attacks on humans are relatively rare. Most species are not aggressive toward humans and play vital roles in ocean health. Public awareness and education about sharks are essential for fostering appreciation and support for their conservation.