A mysterious ocean 'blob', recorded by a deep-sea remote-controlled underwater camera, has been identified as a jelly fish.
When a video of the creature was posted speculators suggested it was everything from the remains of a whale placenta to a fishing net.
However, experts have now confirmed that the ‘sea monster’ is, in fact, a rarely studied jelly fish known as Deepstaria Enigmatica.
The creature created a mystery as it has organs and appendages never spotted on a jellyfish before.
The jellyfish, which are approximately 60cm in width, are rarely seen intact, explains Steven Haddock from the Monterey Bay Aquarium Research Institute.
'This bag-like jelly is not that rare, but is large, so rarely seen intact,' Haddock writes on the JellyWatch Facebook page.
'In the video, the swirling from the sub makes the medusa appear to undulate, and it even turns inside-out.'
Another expert, Craig McClain from the National Evolutionary Synthesis Center, explains that the confusing whitish lumps seen in the video are the jellyfish’s testicles.
The jellyfish was reportedly filmed during deep-sea drilling near the United Kingdom. The species is usually found approximately 5,000 feet below in the south Atlantic Ocean.
Previously it was suggested that the floating blob could be a whale placenta, but the hexagonal shapes on the skin made that unlikely.
Another guess was that the creature might be a Stygiomedusa Gigantea. This type of jellyfish - which can grow up to six metres in length - has only been spotted 114 times in 110 years, so details on it are scant.
But again, the appendages got in the way.
The animal’s brown stomach caused further confusion, as Deepstaria enigmatica are typically colourless, with one description saying the passages to the stomach are 'somewhat irregular-edged, forming a reticulate network'.
The hexagonal markings on the top of the creature led one commentator on the website Snopes - which tries to debunk or confirm rumours - to suggest this is simply nothing more than a fishing net.
Another mystery - a man-made one, this time - is exactly where this video was filmed.
It was added to YouTube on April 27 this year, and appears to have been filmed two days earlier, but the poster did not leave any other details about the sighting.