For biologists, discovering a new species is similar to hitting a grand slam, and biologists at the University of South Carolina have recently cleared the bases with the discovery of a the Carolina Hammerhead, according to school officials.
Joe Quattro, ichthyologist and biology professor, led the team responsible for identifying the new shark, Sphyrna gilberti, which has eluded discovery because it's outwardly indistinguishable from the common scalloped hammerhead.
"Outside of South Carolina, we've only seen five tissue samples of the cryptic species," Quattro said in a statement. "And that's out of three or four hundred specimens."
Quattro made the discovery while researching the genetic diversity of fish in the freshwater rivers of South Carolina as they flow out into the ocean.
While in the process of looking at hammerheads, Quattro and his colleagues uncovered an anomaly. The scalloped hammerheads they were collecting had a unique genetic code that had two different genetic signatures in both the mitochondrial and nuclear genomes from other Hammerhead sharks.
After doing some research, they found that Carter Gilbert, the renowned curator of the Florida Museum of Natural History from 1961 to 1998, had described an anomalous scalloped hammerhead in 1967 that had 10 fewer vertebrae than S. lewini, a common hammerhead species.
It had been caught near Charleston, S.C. and, because the sample was in the Smithsonian National Museum of Natural History, Quattro and his team were able to examine it more closely and suggest that it constituted a cryptic species - that is, one that is physically nearly indistinguishable from the more common species.
Through its rarity, the Carolina Hammerhead, underscores the fragility of shark diversity in the face of relentless human predation.
Quattro said shark populations have greatly diminished over the past few decades.
"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 in a statement. "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."
