New shark species, Carolina Hammerhead, discovered off South Carolina coast
Say hello to the Carolina Hammerhead, a new species of shark.
Thanks to a team of biologists led by Joe Quattro at the University of South Carolina, these predators can be recognized for who they really are. The new species, Sphyrna gilberti, had long eluded biologists because its look is nearly indistinguishable from the scalloped hammerhead.
When Quattro joined the faculty at USC, his research focused primarily on fish in the freshwater river system. It wasn’t until his work reached the Atlantic Ocean that he and his team noticed an anomaly. According to a statement from USC, “the scalloped hammerheads (Sphyrna lewini) that they were collecting had two different genetic signatures, in both the mitochondrial and nuclear genomes.”
It turned out that they weren’t the first ones to notice the slight difference. Carter Gilbert, curator of the Florida Museum of Natural History from 1961 to 1998, had described the new species in 1967 as having 10 fewer vertebrae than S. lewini. Since her findings matched what Quattro and his team had found, they named the new species after Gilbert, hence S.gilberti.
If it seems odd that these two discoveries happened about 50 years apart, it shouldn’t. Not only are the two hammerhead sharks nearly indistinguishable, but the new species is especially rare. “Outside of South Carolina, we’ve only seen five tissue samples of the cryptic species,” Quattro said. “And that’s out of three or four hundred specimens.”
Unfortunately for this new species, however, shark populations over the past few decades have been decreasing. “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.”