Hammerhead shark, is a collective name for the family Hammerhead Shark of the order Eucalyptus, named after the hammerhead shape of its head. The head has two protrusions on the left and right, and the two eyes and two nostrils are located at each end of the protrusion, and there is an instantaneous membrane. The two eyes are 1 meter apart, and such an eye distribution is very beneficial for them to observe the surrounding situation. Not only does it have binocular vision like a human (the visual fields of both eyes overlap), but by swinging your head back and forth, you can also see what is happening within 360 degrees of your surroundings.
Adults can grow up to 3.7–4.3 m long, and females are generally larger than males. The head is wide and flattened, and its front part extends to the sides, forming a T-shaped shape, also known as the "hammerhead shark", which is believed to have the role of a rudder and increase maneuverability. The first dorsal fin is very tall and distinctly sickle-shaped, while the second dorsal fin is much smaller with concave edges. The back is dark brown and light grey. Near the male's anus, there is a pair of organs called copulating processes, and there is a groove on the inside of the copulatory process through which the male directs semen into the female.
It is widely distributed in temperate and tropical seas, and is a common shark species in the ocean. Frequently found on beaches, bays and estuaries, it searched for food in coral reefs and fed on small and medium-sized fish, cephalopods and crustaceans. It is a migratory fish that, when the seasons change, they form a very large migration procession and make a long journey, migrating to temperate seas in the summer to escape the heat, and migrating to tropical seas for wintering in the winter. It is also a dangerous shark with a ferocious temperament, and there are incidents of hammerhead sharks attacking humans every year.