In a flash, he slipped the droopy mouthed, eel-like fish into a pocket of his scuba outfit.

Now, the six-inch fish is being heralded by Bishop Museum tropical fish expert John E. Randall as a new species in the genus Grammonus. Other Grammonus species are found in waters from Japan to South Asia, the Gulf of Aden and even the Mediterranean.

But Randall says Hughes' fish, which the biologist first photographed in 1998, is a unique species. The brownish fish has fins along its rear that make it look similar to an eel, and its mouth is turned down like a grumpy old man.

Randall says he and Hughes are preparing a scientific paper on the fish in the process aimed at getting it recognized and bestowing a name on the species.

Hughes said he's interested in protecting fish along the Kona coast that is threatened by development.

"This shows that there's a very good chance there are other species that we haven't discovered," he said.

Hughes said he caught the fish in July and another one in April, but a tropical fish dealer threw that one away, thinking it had no value because it was dead.

Randall said another biologist, Bronson Nagareda, also has caught one of the fish off the Wai'anae Coast of O'ahu and sent it to him shortly after Hughes found his.

He said it was apparent from the photo taken in 1998 that the fish was a new species, but he couldn't make a scientific determination from a photograph and needed a specimen to document it.

One unusual characteristic of the fish is that it gives birth to live young, like some freshwater fish, such as guppies, Randall told West Hawaii Today, which first reported the find in its Saturday edition.

He said it also has a system of pores along its body that allow it to sense and slight water movement.

"It's an interesting feature, and probably one used to detect the presence of predators and hunt for prey because it is a completely dark environment," he said. "The fish has to rely upon its sense of movement rather than sight."

Randall said other divers have probably seen the fish but they didn't know what to look at.