Carolina Hammerhead: New Species of Shark DiscoveredBy: Mike Fossum - November 8, 2013
A rare new species of hammerhead shark has been discovered off the coast of South Carolina, aptly named the Carolina Hammerhead. A team of researchers from the University of South Carolina discovered the new shark, which was quite a find, considering that the Carolina variant is outwardly indistinguishable from the common scalloped hammerhead sharks.
Joe Quattro, ichthyologist and biology professor in USC’s College of Arts and Sciences, accidentally came across Sphyrna gilberti, the scientific name for the new fish, while surveying shark populations off the Carolina coast. While combing through scores of genetic data from scalloped hammerheads, or Sphyrna lewini, Quattro and his team noticed an anomaly – there were two different genetic signatures in both the mitochondrial and nuclear genomes. Though, the Carolina Hammerhead DNA is rare, and also indicative of a declining hammerhead population as a whole.
“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.”
In the clip below, a Guidos anglerzz lands a “winghead” by its cephalofoil:
After mulling over the new discovery and poking around a bit, the USC team figured out that there was a previously documented anomalous hammerhead that had been captured in 1967. This specimen, which had 10 fewer vertebrae than Sphyrna lewini, was described by Carter Gilbert, curator of the Florida Museum of Natural History from 1961 to 1998. The shark was caught near Charleston, S.C., and catalogued in the Natural Museum of Natural History.
Quattro and his team were able to morphologically examine the specimen, and deemed that it represented a cryptic species, or a species that is almost identical to the more common species. Early genetic evidence of the new variation of hammerhead was published in the Journal of Marine Biology in 2006. After thorough measurements, Sphyrna gilberti, named in Gilbert’s honor, was finally announced in the journal Zootaxa recently.
The defining morphological difference between the common and cryptic species lies in ten missing vertebrae. This mutation can be added to the annals of crazy fish-lore overtaking the news of late.
Image via Wikimedia Commons.