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The Giant Phantom Jelly (Stygiomedusa gigantea)

This jellyfish is potentially one of the largest predatory invertebrates in the world, yet has rarely been observed. Being seen only 110 times in 110 years between 1899 and 2009, there are not a lot of data about this fascinating species. So let's see what we can find out about this huge and mesmerizing jellyfish!

Physical Description and Behavior

The phantom jelly is massive, sporting a bell more than a meter (3.3 feet) across, and with 4 arms that are up to 30 meters (33 feet) long. These tentacles look like ribbons and are often described as "paddle-like" due to how they flutter through the water. Here is a closer view of these majestic arms:

Fun fact: They also use these arms to eat! It is believed that they do this by snagging prey in their long arms and hoisting the prey up to their mouth. This is made easier through the use of nematocysts in order to stun their prey. While it is not entirely known what the diet is for this jellyfish, expert opinion seems to be that their diet consists of small fish and plankton.

Their life history seems to be fairly unique as well. Instead of alternating between their medusa and polyp stages like most jellyfish, the giant phantom jelly covers their young in their huge bell. As a result, they "give birth" to young that are already at their medusa stage.

While the color of the giant phantom jelly is a faded red, since red light does not penetrate this far down into the ocean, these jellies just blend into the background. That said, they do seem to let off faint red bioluminescence. It is not known why they emit this glow, but it is known that bioluminescence is not uncommon among deep-ocean jellyfish.

Habitat and Location

Despite rarely being seen, it is believed that this jellyfish is rather common, and can be found all across the globe. The map above shows 109 sightings of this jellyfish, showing it to be almost entirely observed in the Southern Ocean, but can also be seen near places such as the United States, France, Spain, Africa, India, and New Zealand.

However, this does not mean that the phantom jelly is mainly situated in the Southern Ocean. It could just be that these sightings were made by coincidence due to research that has been going on in the deep oceans of the Antarctic, such as those by the Scientific Committee on Antarctic Research (SCAR). We do know that they prefer to reside in the deep ocean, being seen as deep at 6600 meters deep (or about 1.2 leagues under the sea).

Due to its rarity, not much research has been done on this species, meaning that also has never been assessed by the IUCN Red List.

You can see this species in action by checking out the video below!

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