Hammerhead sharks are marine and coastal, occasionally in brackish waters. They live in all oceans, but especially in the warm ones. Their head is very laterally expanded, with eyes and nostrils much more widely separated than in other sharks; this cephalic structure probably serves to increase its sensory abilities. They have no spiracles. The giant hammerhead shark (Sphyrna mokarran) can exceed 6 m in length and weigh almost half a ton.The range of the nine known species is 0.9 to 6 m long. In general they are light gray and have a greenish hue. Their bellies are white, which allows them to be near the bottom of the ocean and mix when they sneak up on their prey. Their heads have lateral projections that give them a hammer shape.
The positioning of the eyes, mounted on the sides of the distinctive hammer, can give binocular vision, as well as a 360 degree view in the vertical plane, which means that you can see above and below them at all times. The shape of the head can help the shark find food and allows a sharp turn movement without losing stability.
Hammerhead sharks have seven senses. One of them, which humans do not possess, is to detect frequency waves caused by movements of fish and dives over great distances from the sea. Another sense is to detect the electric fields generated by the fish and thus be able to find dams buried in the sand or over great distances. In addition, your nose is able to detect a drop of blood over long distances.
They can form groups of more than one hundred hammerhead sharks. At night, like other sharks, they become lonely hunters. Since sharks do not have mineralized bones and rarely fossilize, only teeth are normally found as fossils.