Mysterious sea creature identified as placental jellyfish

For two years a mysterious sea creature has been captured on video as it swims 5,000 feet below the surface, but scientists have been in the dark as to what exactly it is. Now, the mystery is solved: it is a placental jellyfish -- after many arguments and speculations. NBC reports, "They believe it is a rarely seen jellyfish plodding its way, not at great speed, through the Gulf of Mexico. The video was actually shot by an underwater gulf rig camera."

The fish's species was, at first, hard to identify because it appeared to have no eyes, mouth, tentacles, front or back.

NPR reports scientists first believed it might be a whale placenta. They ruled that out because it would have been a large target for predators at that depth and likely would have been eaten sooner. Then Deep Sea News Chief Editor Craig McClain noticed the creature had a sex organ similar to a giant jellyfish called Deepstaria enigmatica.

Case solved? Not quite.

According to the Daily Mail, it was a small detail -- the hexagonal pattern on the creature's skin -- that gave strong evidence that this jellyfish is actually a Deepstaria reticulum, or a placental jellyfish.

The species is native to Antarctic waters, which are significantly colder than the Gulf of Mexico. Scientists don't know how or why this particular jellyfish ended up in the Gulf.

When we think of exploration, we normally think of space, but perhaps even greater mysteries lie in our oceans. The National Oceanic and Atmospheric Administration says oceans cover 70 percent of our planet's surface, yet 95 percent of it remains unexplored.

Odds are the oceans contain many other incredible mysteries to be solved and unfamiliar creatures to identify.

See more footage of the Deepstaria reticulum below:

Speaking of sea creatures, check out this friendly shark.