The Stygiomedusa gigantea, seen above in a video from the Monterey Bay Aquarium Research Institute (MBARI), has been spotted in almost every ocean in the world. Its sheer size (up to ten metres) is not the only characteristic that sets it apart from other jellyfish, it also has no tentacles. Instead, four great curtain-like folds make up its gelatinous body, giving it the colloquial name of “ghost jellyfish.”
The grandly sized “arms” glide behind the jellyfish in a soft yet surreal manner, resulting in a hypnotic movement, much like drapes being billowed by a gust of wind.
Another spectacular element of this creature is its colour. The Stygiomedusa’s red colouration helps it stay out of sight against the black backdrop of the deep sea. It appears red near the surface, because all spectra of sunlight can reach its body. The jellyfish absorbs all the other colours of light, and reflects only red.
However, deeper down in the sea (where this jellyfish is truly at home), upto 2,187 metres below, red light is much too weak to penetrate. As a result, there is nothing to reflect and the ghost jellyfish quite literally disappears. It has only been observed a total of seven times over the 27 years that the remotely operated vehicles of the MBARI have been combing the deep seas.
The “Deepstaria” jellyfish has also been dubbed a ghostly creature, and like the Stygiomedusa gigantea, doesn’t have tentacles. It was spotted more than 2,500 feet (762 meters) below the central Pacific Ocean by the Ocean Exploration Trust during an exploration aboard the vessel Nautilus. Below is a video of the shape-shifting Deepstaria while a crustacean actually eats it from the inside: