Scientists discover deadly, highly venomous box jellyfish near Singapore’s ‘Island of Death Behind’
Scientists described a new species of highly venomous box jellyfish based on specimens that lurked near a Singapore island formerly known as Pulau Blakang Mati, or “the island of death behind,” in 2020 and 2021.
The newly described species, Chironex blakangmatiowes its name to the original, ominous name of the island in Malay, rather than its name since 1972, Sentosa, which means “peace and tranquility”. This is normal, given the danger the animal represents.
Previously, scientists were wrong C. blakangmati for another species of box jellyfish, C. yamaguchii. However, it turns out that these canned jellies are different, both genetically and morphologically, scientists reported in a new study published May 15 in the journal Zoology Raffles Bulletin.
“C. blakangmati looks remarkably like Chironex yamaguchii — a species of jellyfish that I discovered for the first time in Okinawa while I was doing my master’s there”, co-author of the study Cheryl Amesprofessor of applied marine biology at Tohoku University in Japan and research associate at the Smithsonian National Museum of Natural History in Washington, D.C., said in a statement. statement. “But we realized they were completely distinct. In fact, I went back and dusted off an old sample of C. yamaguchii I still had some in stock in Okinawa to make comparisons easier!”
The researchers found that the newly identified species lacks branched canal structures at the bottom of its bell-shaped body that C. yamaguchii and the other two Chironex species, C. fleckeri And C. indrasaksajiaeexposure. Specifically, these channels are found in perradial lappets, which are flaps reinforcing the musculature that propel box jellyfish when they swim. Combined with genetic divergence, this anatomical difference confirmed that C. blakangmati is a distinct species, according to the release.
“Our in-depth review and analysis of all Chironex The species known to date reveal a lot about these box jellyfish,” study co-author Dan Wei Huangassociate professor at the Department of Biological Sciences at the National University of Singapore and the Lee Kong Chian Museum of Natural History, said in the statement.
The analysis was based on jellyfish specimens washed up on Singapore beaches in 2020 and 2021. New species are marked in blue, while Thai sea wasps are shown in red.
The results also revealed for the first time that C. indrasaksajiaewhich is usually found off the coast of Thailand, is present in Singapore waters. Nicknamed the Thai sea wasp, this species can be deadly.
“We were surprised to see C. indrasaksajiae so far from Thailand,” Ames said. “Range expansion like this is really important because we currently know so little about the biodiversity and spatial distribution of box jellyfish.”
A better understanding of the distribution of canned jellies could help prevent serious injuries and deaths in humans, the release said.
Records suggest that box jellyfish stings cause around 40 deaths a year worldwide, but some experts think this figure is a huge underestimate.
Iesa, I., Ames, CL, Yap, NWL, & Huang, D. (2026). Chironex box jellyfish (Cnidaria: Cubozoa: Chirodropida) in Singapore: Chironex blakangmatinew species and range expansion C. indrasaksajiae. Raffles Bulletin of Zoology. http://dx.doi.org/10.26107/RBZ-2026-0026
