New blue jellyfish species, nicknamed as "samurai jellyfish" found in Japanese waters

Bright Blue Samurai Jellyfish Found in Japanese Waters (Image: Karen H Black)

A striking new jellyfish species has been discovered off Japan’s coast. Its vivid blue colour and crescent-shaped float immediately caught scientist's attention. Researchers say it represents a previously unknown venomous marine organism in the region.

What Was Discovered?

Japanese researchers identified a new jellyfish species named Physalia mikazuki. It is nicknamed the “samurai jellyfish” for its crescent-shaped float. The species is bright cobalt-blue, unlike its tropical relatives. It is venomous and capable of delivering painful stings to humans.

Why named as “Samurai”?

The crescent-shaped float resembles the helmet of samurai lord Date Masamune. The name “mikazuki” translates to “crescent moon” in Japanese. This unique shape sets it apart from other Portuguese men-of-war.

How Was It Found?

Scientist Yoshiki Ochiai was working on a different research project around Sendai Bay in Japan’s Tohoku region when he happened upon a curious-looking jellyfish. The specimens were examined using morphology and DNA analyses. Both tests confirmed it as a distinct species, not a variant.

Where Did It Come From?

Ocean currents, especially the Kuroshio Current, likely carried it north. Warming sea temperatures may have enabled range expansion of this tropical species. Climate change could allow more venomous species to appear in new areas.

What this discovery reveals?

The discovery reveals how ocean ecosystems are shifting in warming seas. It highlights safety risks for swimmers and the need for awareness. Studying the species helps understand climate-driven changes in marine biodiversity.