Rare New Species of Carolina Hammerhead Shark Discovered

Discovering a new species may seem like an uncommon occurrence in our modern world. After all, researchers have plumbed the depths of the oceans and have explored some of the most remote rainforests and mountain regions on the planet. Yet it seems that there are still species that have yet to be exposed. Scientists have now announced that they've discovered a new species of rare shark, the Carolina hammerhead.

The Carolina hammerhead has long eluded discovery due to the fact that it is outwardly indistinguishable from the common scalloped hammerhead. The new species, named Sphyrna gilberti, was actually discovered as scientists were looking for more common hammerheads.

South Carolina is a well-known pupping ground for several species of sharks, which means that researchers were collecting samples there for study. The female hammerhead will birth her young at the ocean-side fringes of the estuary; the pups then remain there for a year or so as they grow before moving out to the ocean to complete their life cycle.

In the process of looking for hammerheads, though, the scientists quickly discovered an anomaly. The scalloped hammerheads that they were collecting had two different genetic signatures in both the mitochondrial and nuclear genomes. After doing a bit of research, the scientists found that the anomalous scalloped hammerhead had been described in 1967 and had 10 fewer vertebrae than the normal scalloped hammerhead. Intrigued by this fact, the researchers examined a museum specimen morphologically.

In the end, the scientists found that there was genetic evidence to show that this hammerhead was, in fact, a new species. Unfortunately, scientists aren't sure exactly how many individuals still exist in the wild.

"Outside of South Carolina, we've only seen five tissue samples of the cryptic species," said Quattro, one of the researchers, in a news release. "And that out of three or four hundred specimens. The biomass of scalloped hammerheads off the coast of the eastern U.S. is less than 10 percent of what it was historically. 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."

The findings are published in the journal Zootaxa.