New species of hammerhead shark found in US waters

A new species of hammerhead shark has been discovered in the north-western Atlantic off the coast of South Carolina.

The shark, which resembles a common species called the scalloped hammerhead, has yet to be classified or named. Like all existing representatives of the species' family, it is dark in colour with a T-shaped "hammer" protruding from its head. Researchers say it appears to be rare, breeding only in waters off the US coast.

The man who made the discovery, Dr Joe Quattro, a biology professor at the University of South Carolina, developed an interest in the common scalloped hammerhead shark while studying coastal sealife with experts from the region. Genetic studies revealed the waters concealed a similar but unknown "cryptic" species - that is, genetically unrelated. While the only aesthetic difference is the number of vertabrae, the genes in the DNA differ significantly.

"This shark is genetically distinct," said Dr Quattro, whose research was published recently in the journal Marine Biology.

The species is the ninth recognised in the hammerhead family. Dr Quattro and his research team found it is not as abundant as the scalloped hammerhead, often seen off the coast of South Carolina. Although adult sharks of the new species were found off the neighbouring states of Florida and North Carolina, only shark pups appear to be showing up in South Carolina's coastal waters.

"The apparent abundance of the new species in coastal South Carolina could be a result of sampling but it might also highlight the fact that the South Carolina bays are important nursery grounds" Dr Quattro said.

Although scientists don't know why the the female of the species has chosen South Carolina as its birthing pool, Dr Quattro believes something as simple as salinity differences or tides may be a factor. Marine biologists plan to tag the sharks this summer so they can learn more about it.

Marie Lavigne, of the Shark Research Institute, said the discovery was significant. "It's exciting news. It's made more exciting by the fact that it wouldn't be possible without today's genetic advancements."

The finding brings the number of recorded species of shark in the wild to 455.

In March, a new species of smooth hound shark -Mustelus hacat - was identified in the heavily fished Gulf of California, highlighting the importance of protecting species from overfishing and pollution.

Hammerheads are considered potentially dangerous sharks but are believed to attack only when confused or threatened. The International Shark Attack File documents 21 unprovoked attacks with two resulting fatalities for all species of the family. Most incidents result from accidental collisions with the protruding "hammer"' in deep waters.

Although shark attacks do occur off the South Carolina coast, Dr Quattro believes the focus should be on preserving, not fearing, hammerhead sharks. Because the new species appears to have a sparse geographic distribution, it is at greater risk of extinction, and conservation efforts are needed.

Dr Quattro said: "If these sharks gather here to reproduce, these areas should be conservation priorities. Management plans are needed to ensure these sharks are not adversely impacted so that we can learn more about them."