A new study in the journal Nature Communications reveals that hammerhead sharks resemble lazy human swimmers by swimming on their side.  According to the study’s international team of researchers, hammerheads engage in this behavior in a bid to conserve energy.

The research team initially thought that the hammerhead sharks off Australia, Belize and the Bahamas were sick but they found that the endangered animals were simply switching from one side to the other while swimming. When they attached video cameras to five sharks, the team realized that the hammerheads actually spend 90 percent of the time swimming at angles of between 50 and 70 degrees.

The researchers concluded that this technique reduces drag and saves energy. When the hammerheads tilt to the side, their dorsal fin, which is longer than their pectoral fins unlike other sharks, generate lift, thereby allowing these animals to swim more efficiently.

Experiments using models of great hammerhead sharks confirm that the animals experience the least amount of drag and spend the least amount of energy by swimming at these angles. Overall, the researchers estimate that this technique helps sharks conserve up to 10 percent energy.

“The animals reduce the cost of transport by about 10 percent by using the side-swimming method” compared with traditional upright swimming,” says the study’s co-author Adam Barnett from James Cook University in Australia.  “It just goes to show how much we don’t know about what goes on in the ocean.”

Although this discovery helps us know more about hammerheads, how they behave in the wild remains unfamiliar to us. We still need to study more about the other traits that set the hammerheads apart from other shark species.

Unfortunately, according to the study’s lead researcher Nicholas Payne from the University of Roehampton’s Department of Life Sciences in London, studying the sharks in the wild is becoming increasingly difficult. Hammerhead sharks are disappearing and in need of saving.