BE CAREFUL!: Japan’s Most Venomous Creature

  • LIVE and WORK
  • Japan is a beautiful country. The archipelago contains multiple islands, and it’s of extreme importance to know, respect, and understand the wildlife that abounds here.

    For that reason, it is of extreme importance to realize that Japan is home to various animals that can possess danger to humans if an interaction with them them occurs. Most of these animals are found down south, in the Ryukyu Islands. This is understandable, since the tropics tends to be notorious for the array of venomous animals that live in forests and tropical waters.

    Box Jellyfish – Habu Kurage

    Commonly known in Japan as Habu Kurage or Habu Jellyfish, the box jellyfish is an extremely dangerous creature. These jellyfish are the most common ones in the waters around Okinawa, particularly when temperatures get warmer. This can create a lot of trouble since those months are peak season, when tourists flock to Okinawa to enjoy the weather and beautiful beaches.

    To make things worse, box jellyfish are very difficult to see because they are semi-transparent. This means that you could be swimming or snorkeling in the paradisiacal waters of Okinawa without knowing that one of these monsters (or a group of them!) is lurking next to you.

    The biggest problem with box jellyfish is that their tentacles have nematocysts containing very potent toxins that can cause serious problems. If you are lucky, getting stung will cause blisters and tissue necrosis… and if we are mentioning tissue necrosis as being lucky you can imagine how bad things can get. We are talking about shock, respiratory arrest, and cardiac arrest. Ergo, habu kurage can kill you.

    What to Do

    If you get stung, don’t rub the area. Use vinegar and remove the tentacles before applying ice or cold water. Don’t hesitate to go to a hospital or clinic to receive proper treatment afterwards. As the saying goes: better safe than sorry.

    It’s also important to stay in the safety zones. Many foreign tourists complain when they notice that beaches around Okinawa have a net that prevents them from exploring deeper waters. Those nets are there for a reason since locals and authorities know the vast numbers of habu kurage that live around the islands.

    You have to remember that not all jellyfish are the same, and habu kurage are not the only species that frequents Japan.

    Portuguese man o’ war are rather beautiful creatures (which are actually siphonophores, not jellyfish) have very long blue tentacles and are extremely venomous. Their stings are extremely painful and can also be fatal. However, using vinegar would be a terrible idea since it would only exacerbate the injury.

    How to Prevent Getting Stung

    As we previously stated, it can be quite difficult to see a habu kurage. Therefore, it’s important to follow certain rules so an encounter with this jellyfish does not prove fatal.

    One thing you can do is wear a rash guard or a swim shirt when swimming. The important thing is to try to cover your skin so that the nematocysts don’t fully penetrate your skin and cause a lot of damage.

    One Box Jellyfish, Two Box Jellyfish

    One thing to remember is that there are many kinds of box jellyfish, and some don’t possess great danger to humans. However, habu kurage are not in that group since they are considered among the most dangerous types of jellyfish. Keep this in mind since the jellyfish that are common to areas you are used to can be extremely different from other species around the world. It’s quite common for people to undermine how dangerous an animal is because of their experiences with a similar one.


    We will keep things simple. Are habu kurage jellyfish dangerous? Yes. Should they dissuade you from going to Okinawa? Absolutely not.

    Follow the guidelines, check the signs, and make sure you know what to do in case of an emergency.