Scientists have described a new jellyfish species with a unique red stomach resembling the Cross of St. George.
According to the research published in Zootaxa journal, the St George's Cross Medusa has some striking features like 240 tentacles and a red cross in its stomach, which seems evident when viewed from above.
Captured in 2002, the scientists identified the new species as Santjordia pagesi, referring to Saint George in Catalan. A remotely operated vehicle (ROV), 812 meters (2,644 feet) deep in Sumisu Caldera, a hydrothermally active deep-sea volcanic structure in Japan's Ogasawara Islands, found the newly described species.
The discovery was challenging as the environment around the volcanic structure is inhospitable and is accessible only through specialised equipment such as ROVs. Another ROV spotted a jellyfish of the same species in 2020 but couldn't capture it.
The St. George's Cross Medusa gets its name from the red cross emblem of England. This medusa is smaller than other species of jellyfish, measuring approximately four inches (10.16 centimetres) wide and three inches (7.62 centimetres) long.
André Morandini, a professor of zoology at the University of São Paulo's Institute of Biosciences, and his team published their findings about the new gelatinous animal in November 2023. The other researchers were from the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) and the Okinawa Institute of Science and Technology (OIST).
"The species is very different from all the deep-sea medusae discovered to date," André Morandini said. "It's relatively small, whereas others in this kind of environment are much larger," he added. Morandini speculated that the red cross on its stomach "probably has to do with capturing food."
The researchers said the classification of S. pagesi within a new subfamily, Santjordiinae, signals the evolutionary divergence and possible novel adaptations. Its unique attributes also question its venomous arsenal, which might exist in this medusa, unlike other known jellyfish species.
"We opted to publish the description and call attention to the species that are present at the site, which has a substrate rich in minerals and the potential to be commercially developed," Morandini said in a press release. "Unfortunately, research can't be conducted in such places without partners who have interests of this kind."