The ghostly giant is an extremely rare sight and now we have excellent footage to help us learn about it.

Out of the darkness of the ocean’s midnight zone, a remotely operated vehicle (ROV) of the Monterey Bay Aquarium Research Institute (MBARI) spots a billowing crimson curtain. When the submersible moves in for a closer look, its lights reveal the outline of a giant jellyfish (Stygiomedusa gigantea).

Known in English as the “giant phantom jelly,” every sighting of this mysterious animal is a celebration for ocean researchers. It was first collected in 1899, but since then scientists have only encountered this animal about 100 times, even though we’re talking about a large animal that appears to have a worldwide distribution. So why the few sightings? Well, accessing these animals’ deep-water habitat has posed a great challenge.

This is where MBARI’s remotely operated devices come into the picture. Such vehicles have meant a great leap forward in learning about deep-sea life and MBARI’s ROV Doc Ricketts has now further added to our knowledge by providing the amazing footage below. The ROV spotted this giant phantom jelly in November 2021, at a depth of 990 meters (3,200 feet) in Monterey Bay. This deep-sea denizen has a bell that measures more than one meter (3.3 feet) across and trails four ribbon-like oral (or mouth) arms that can grow more than 10 meters (33 feet) in length.

Even today, we know very little about the giant phantom jelly. Historically, scientists relied on trawl nets to study deep-sea animals, and while such nets can be effective for studying hardy animals such as squids, crustaceans, or fish, jellies turn into a gelatinous goo in them. The cameras on MBARI’s ROVs, on the other hand, have allowed researchers to study these animals intact in their natural environment. High-definition footage of the giant phantom jelly capture stunning details about the animal’s appearance and behaviors that scientists would not have been able to see with a trawl-caught specimen.

MBARI’s observations of the giant phantom jelly have helped illuminate the animal’s ecological role in the ocean’s depths. During an expedition to the Gulf of California, for example, another MBARI ROV, Tiburon, recorded a fish -the pelagic brotula (Thalassobathia pelagica) – alongside a giant phantom jelly. Researchers watched as the brotula hovered above the bell of its host and swam in and out of the jelly’s enormous oral arms. As the wide-open depths of the midnight zone offer little shelter, many creatures find refuge in the gelatinous animals that are abundant in this environment.

Source: earthlymission.com