A highly venomous new species has been discovered lurking in the waters of a major world city.
The new type of box jellyfish - first found near a Singaporean island in 2020 - has now been described in a new report published in the journal Raffles Bulletin of Zoology.
The new species has been named Chironex blakangmatim by researchers from Tohoku University and the National University of Singapore.
It has been named after the Pulau Blakang Mati island - which translates to "Island of Death Behind".
The name is fitting - C blakangmatim is one of four known species of dangerous Chironex box jellyfish, all of which are incredibly venomous.
Their stings are so dangerous they have been known to kill humans in as little as two minutes.
And unlike other jellies, which simply float with the current, Chironex are capable of actively swimming towards their prey with complex eyes and strong musculature.
The newly identified species had previously been mistaken for the similar box jellyfish C yamaguchii.
Pictures of the new jellyfish species as described by Tohoku University
|TOHOKU UNIVERSITY
But it has now been determined the species differe both genetically and morphologically.
"C blakangmati looks remarkably like Chironex yamaguchii - a jellyfish species I first discovered in Okinawa while doing my master's degree there," co-author of the study Cheryl Ames, professor of applied marine biology at Tohoku University in Japan, said.
"But we realised they were completely distinct. I actually went back to dust off an old sample of C yamaguchii I still had in storage in Okinawa to help with the comparisons," she added in a statement.
Differences between the two species include C blakangmatim's lack of branched canal structures, which all other Chironex display.
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PICTURED: A sign warning of the dangers of box jellyfish in Australia
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This key difference, along with genetic analysis, confirmed it was a newly discovered species.
"Our thorough review and analysis of all the Chironex species known to date reveal a lot about these box jellyfishes, and highlight a new, helpful strategy that other researchers can use for species delineation," co-author Danwei Huang, associate professor at National University of Singapore's Department of Biological Sciences said.
Analysis of the various box jellyfish species revealed further insights about the spread of the dangerous genus.
Reserarchers discovered the Chironex indrasaksajiae, normally found off the coast of Thailand, had also been found in SIngaporean waters.
C. blakangmatim has becomes the fourth known Chironex species, which includes the Australian sea wasp (pictured)
|GETTY
This deadly species - nicknamed the Thai sea wasp - was responsible for the death of an Israeli boy in 2021.
Dr Ames said: "We were surprised to find C indrasaksajiae so far away from Thailand.
"Recording range expansions like these is really important, as we currently know so little about the biodiversity and spatial distribution of box jellyfish."
A better understanding of the ecology of the box jellies could be used to create better safety guidelines for beachgoers who may encounter them, Tohoku University said.