Scalloped hammerhead sharks have sleek, slender bodies, which are typically grey in color. This is a smaller species than the great hammerhead and is named for the wavy scallops on the front of its head (also known as a cephalofoil). The eyes and nostrils are located at the ends of the cephalofoil. Adult males may reach a length of 6 feet (1.8 m) and females can reach over 8 feet (2.43 m).
Scientists are still studying this shark’s reproductive cycle. It is likely that females can give live birth to at least once a year, producing up to 30 pups. Scalloped hammerheads often use nursery areas for their young where the adults aren’t present. It is assumed use of nursery areas stop pups being eaten by adults of their species.
Unlike the great hammerhead, it is common to find these fish swimming together, even in schools numbering hundreds of individuals. Schooling behavior appears to be related to hunting with younger, less experienced sharks staying at the top of the school while learning from older sharks. Because of their very high metabolic rate, a scalloped hammerhead needs to eat almost constantly and may starve quickly if it does not.
This shark can be found along the coastline during the day and will retreat further out to sea at night to hunt cephalopods, sardines, mackerel and herring. They may occasionally take another shark, too. They generally do not dive deeper than 1,600 feet (500 m).
This species is endangered around the world. Hammerheads are still victims of “finning,” a harvesting practice where the fins are cut off the live shark and sold in Asian food markets. Although finning is illegal in Australian waters, it continues in some parts of the Pacific, and along with diminishing food sources and habitat destruction, contributes to the shark’s declining population.