A rare sighting of a giant jellyfish has been caught on camera at a depth of 975 meters in Monterey Bay, off the coast of California, United States.
The footage was captured by Monterey Bay Aquarium Research Institute (MBARI) scientists using a remote-operated vehicle (ROV). This is one of nine times the giant jellyfish Stygiomedusa gigantea has been observed by MBARI.
The 53-second video shows a brownish jelly-like creature floating around the bay, and its arms trailing behind it as it moves away.
"This deep-sea inhabitant is more than a meter wide, not counting the four ribbon-like mouth (or mouth) arms that can grow to more than 10 meters," MBAIR was quoted as saying by News Week.
"Giant jellyfish were first collected in 1899. Since then, scientists have only encountered this animal about 100 times. Apparently, this creature has a worldwide distribution and has been recorded in all ocean basins except the Arctic," added MBAIR.
The researchers also mentioned that accessing the depths of the ocean where these jellyfish live is also a challenge. Hence, aquatic habitats contribute to the scarcity of sightings for such a large and widespread species.
Stygiomedusa gigantea is considered one of the largest invertebrate predators in the deep sea. This creature once appeared off the coast of Mexico in 2010.
Then more footage of the giant jellyfish emerged in 2015, and Stygiomedusa giganteaphantom was filmed in the Gulf of Mexico. Before ROVs were widely used, scientists relied on trawl nets to find and study deep-sea species.
"This net is effective for studying tough animals such as fish, crustaceans and squid, but jellyfish turn into a gelatinous liquid in trawl nets," said MBAIR.
The camera on the MBARI ROV has allowed MBARI researchers to study these animals in their entirety in their natural environment. This high-definition video of the jellyfish captures stunning details about the animal's appearance and behavior that scientists are unable to see with specimens caught by trawlers.
Jellyfish is one of the creatures that can survive in the great depths of the ocean. In 2016, researchers discovered a species of glowing jellyfish living near the Mariana Trench.
This jellyfish, which informally goes by another name Enigma Seamount, is described as having a height of 3,700m. The largest known jellyfish is the lion's mane jellyfish Cyanea capillata, which has tentacles that can stretch up to 36 meters.