Scientists discovers new highly venomous box jellyfish species with stings strong enough to kill humans

Scientists have identified a new species of highly venomous box jellyfish after studying specimens found near a Singaporean island that was formerly known as Pulau Blakang Mati, or the "Island of Death Behind," in 2020 and 2021.

The newly discovered species has been named Chironex blakangmati, taking inspiration from the island’s original Malay name rather than its current name, Sentosa, which was adopted in 1972 and means "peace and tranquility." The name is considered fitting due to the potentially dangerous nature of the jellyfish.

C. blakangmati is now recognised as one of four known species belonging to the Chironex box jellyfish group, all of which are known for their powerful venom. Their stings are delivered through specialised cells on their tentacles called nematocysts, which can be strong enough to kill humans.


Unlike many jellyfish species that drift passively with ocean currents, Chironex box jellyfish are active swimmers. They can detect and move towards prey using their strong muscles and advanced vision system, which includes complex eyes.

Previously Mistaken for Another Jellyfish Species

Before its official identification, scientists had mistakenly classified C. blakangmati as another species, Chironex yamaguchii. However, researchers found that the two species differ genetically and physically, according to a new study published on May 15 in the journal Raffles Bulletin of Zoology.

The researchers discovered that the newly identified species does not have the branched canal structures found at the base of the bell-shaped body in C. yamaguchii and the other known Chironex species, including C. fleckeri and C. indrasaksajiae.

These canals are located within the perradial lappets, which are muscular flaps that help strengthen the jellyfish’s swimming ability. Along with genetic differences, this unique anatomical feature confirmed that C. blakangmati is a distinct species.

Deadly Thai Sea Wasp Species Also Found in Singapore Waters

The study also revealed, for the first time, that C. indrasaksajiae, a species usually found near Thailand’s coast, is also present in Singapore’s waters.

Known as the Thai sea wasp, this species can be deadly due to its venomous sting. Scientists believe that better knowledge of box jellyfish distribution can help reduce the risk of serious injuries and fatalities among humans.