By Ananth Baliga
A new species of hammerhead shark discovered off the coast of South Carolina previously eluded researchers because of its similarity to the common scalloped hammerhead.
Ichthyologist Joe Quattro, a biology professor with the University of Carolina, came across the new species while looking at hammerheads in South Carolina. The scalloped hammerheads they were following displayed two different genetic signatures.
On searching through literature they found that Carter Gilbert, curator of the National Museum of Natural History from 1961 to 1998, had described a scalloped hammerhead to have 10 less vertebrae, the distinguishing feature for this new species.
Quattro was drawn to Carolina after his work documenting species in the rivers of South Carolina led him to the ocean. South Carolin is well-known a pupping ground for several species of shark, including the hammerhead. The female hammerheads would birth their offspring close to coast and remain there for a year while the pups grew.
After publishing in 2006 genetic evidence of this new species, they followed it up with making measurements of the new species and named it Sphyrna gilberti, named in honor of Gilbert.
While shark populations have dwindled over the years Quattro hopes his work will go a long way to help document this dying species and increase awareness about the taxonomy and evolutionary history of sharks.
"The biomass of scalloped hammerheads off the coast of the eastern U.S. is less than 10 percent of what it was historically," Quattro said. "Here, we're showing that the scalloped hammerheads are actually two things. Since the cryptic species is much rarer than the lewini, God only knows what its population levels have dropped to."