March 13, 2006—It may have been seen thousands of times by fishermen, but this new species of shark was officially discovered by scientists only recently in Mexico's Gulf of California.

The shark was found in a deep-sea fishing catch in 2003, making it the first new shark species to be identified in the gulf in over 30 years. The discovery was announced in the journal Copeia in December.

The species, known as Mustelus hacat, grows up to three and a quarter feet (one meter) long and lives at depths of more than 650 feet (200 meters).

Biologist Juan Carlos Perez of Ensenada, Mexico, identified the species while studying smooth hound sharks, a family of slender, bottom-feeding sharks that live in the gulf's deeper regions.

While examining the catch from commercial fishing trawlers, Perez spotted some smooth hound sharks whose unique markings made him take a closer look.

"They got my attention with their dark gray-brown color and the conspicuously white tips and trailing edges on [their] fins," Perez said.

Smooth hounds are well known to local fishermen—in some areas they account for 80 percent of a day's catch—so it's possible that the newfound shark had been caught before and not recognized as a distinct species.

Perez points out that Mustelus hacat may be just one of countless species that have yet to be discovered in the heavily fished Gulf of California, also known as the Sea of Cortez.

"I think this discovery reinforces the importance of the Sea of Cortez," Perez said, "because probably there are other undiscovered species that could disappear before we find them."

—Blake de Pastino and National Geographic !