Ghostshark photographs courtesy MBARI (top) and by Kelsey James (bottom)
Ghostshark photographs courtesy MBARI (top) and by Kelsey James (bottom)

Weird New Ghostshark Found; Male Has Sex Organ on Head

Flying for years under the scientific radar, the new ghostshark species is among the world's oldest and and oddest fish.

California has a new star, the Eastern Pacific black ghostshark.

But the newly identified species prefers to stay out of the sun—and the spotlight. And with a club-like sex organ on its forehead, the male ghostshark isn't likely to get any leading man roles.

Pictured alive underwater (top) and preserved in a museum collection (bottom), the new ghostshark uses winglike fins to "fly" through its dark habitat, thousands of feet deep off the coasts of California and Mexico's Baja California peninsula, a new study says.

The ghostshark seems to have flown under the scientific radar too. Since the 1960s experts have been finding specimens of the strange, 3-foot-long (0.9-meter-long) fish, which ended up nameless in museum collections around the world.

It wasn't until after a team recently searched through shelves of "dead pickled fish" that the Eastern Pacific black ghostshark was recognized as its own new species, said study co-author Douglas Long, chief curator in natural sciences at the Oakland Museum of California. The specimens' unique proportions, precisely measured, gave the fish away as a separate species of ghostshark.

Ghostsharks in Chimerical Company

The shark-like animal belongs to the mysterious and little-studied chimaeras, perhaps the oldest group of fish alive today.

These "living fossils" branched off from sharks about 400 million years ago. They may have survived by adapting to extreme deep-sea environments, Long said.

The newfound ghostshark belongs to the "big black chimaeras," a group whose species number has exploded in recent years, thanks to improved diagnostic techniques, according to the new study, published in the September issue of the journal Zootaxa.

Chimaeras display some unusual features not seen in other living animals, Long said.

Male chimaeras, for example, have retractable sexual appendages sprouting from their foreheads. These organs, which resemble a spiked club at the end of a stalk, may be used to stimulate a female or to pull her closer—though these are still assumptions, Long said.

Long said the odd fish shows how complex the deep ocean can be—as well as the vast potential for encountering weird new creatures.

"It's like Christmas. You don't what you're going to get," he said, "but you know it's going to be great."