LOS ANGELES -- A 14-foot oarfish that washed ashore in Southern California last week was ready to become a mommy.

The serpent-like fish -- one of two discovered along the coast last week -- was dissected Monday and marine biologists found that the healthy female was ripe to spawn, H.J. Walker of the Scripps Institution of Oceanography said Tuesday.

The silvery fish's 6-foot-long ovaries contained hundreds of thousands of eggs that were nearly ready to be released, Walker said.

The fish had lost its tail somehow while alive and it had disc-shaped wounds from cookiecutter sharks, but those injuries wouldn't have been deadly, Walker said.

In fact, it's unclear why the creature died, although Walker said it was possible the deep-water fish came too close to the surface, where it may have been knocked around by waves.

The oarfish washed up on a beach in the San Diego County coastal city of Oceanside on Friday. Several days earlier, a snorkeler found the carcass of an 18-foot oarfish off Catalina Island and dragged it to shore with some help.

The cause of death for the larger fish also remains a mystery.

The rarely seen deep sea-dwelling creatures, which can grow to more than 50 feet (15 metres), may be the inspiration of sea monsters found in literature and throughout history. Photos of the oarfish have circulated widely online, spurring general interest in the mysterious creature but contributing little to scientists' knowledge of the fish.

Here's a closer look at the oarfish:

How often do they venture close to shore?

Oarfish beach themselves around the world. Every so often, one wanders to the Southern California coast.

How did the two oarfish die?

While necropsies -- the animal version of an autopsy -- were done on the oarfish, the cause of death remains unknown. Scientists said the deaths may forever remain a mystery. The smaller oarfish appeared to be in good health before it died and there were no signs of shark bites.

Oarfish are thought to be poor swimmers, so maybe the ones found last week got caught in a current that pushed them to coastal waters, marine experts said.

"If they get disoriented and into the surf zone, they'll probably have trouble manoeuvring back out to sea," said Phil Hastings, curator of the marine vertebrate collection at the Scripps Institution of Oceanography.

Why is so little know about oarfish?

Oarfish tend to remain quiet in the deep ocean, luring smaller fish toward them.

Since they are found in tropical waters 3,000 feet deep, scientists get few opportunities to study them. The dead oarfish that float ashore don't tell the whole story. It's like trying to study deer killed on the road, said Milton Love, a marine biologist at the University of California, Santa Barbara.

"You wouldn't know much about deer based on roadkill," he said.

What's next?

Scientists have dissected the oarfish, preserved some tissue and organs, and planned to send samples to researchers around the world.