Beware of titan ballista! (Thailand, February 2006)
Beware of titan ballista! (Thailand, February 2006)

Beware of the ballista!

  Indonesia: Bali - July 2008

Dear English-speaking readers, this page is an automatic translation of an article originally written in French. I apologise for any strange sentences and funny mistakes that may have resulted. If you read French, click on the French flag below to access the original, correct text: 

Everyone is afraid of sharks. This is silly. It is rare that sharks eat humans (while the opposite is not the case). In fact, there is much more dangerous for divers: the mustache triggerfish or olive triggerfish, also called titan triggerfish.

A fast and sometimes aggressive fish

Those who have already felt its teeth, remember it...

The triggerfish is a fairly large fish (50 to 75 cm long), very fast. It is called trigger-fish in English, because of its caudal fin which is pointed like a trigger when it goes into action.

Titan triggerfish
A titan triggerfish surrounded by small reef fish.

It is one of the few fish that divers can fear attacks ... with, of course, the fierce clownfish !!!


Admire below the teeth of the beast... And the little cleaning shrimp, perched fearlessly on the tip of its "nose"!

The triggerfish leaves the small shrimp cleaners to rest on his jaws with sharp teeth. (Malaysia, Perhentian Islands, July 2006)
The triggerfish leaves the small shrimp cleaners to rest on his jaws with sharp teeth. (Malaysia, Perhentian Islands, July 2006)

This photo is dated my 2006 trip to the Perhentian Islands, Malaysia. A very wise ballista like that, the time of the passage to its "cleaning station", it is not so frequent...

Video: the ballista's meal

Below, shot at Bali in July 2008a short video of the beast, biting the reef to pieces:

Stay away from the "nest".

In fact, it is aggressive after the mating season and the laying of eggs, when it guards the nest. If you get too close, the titan triggerfish (usually a female) will attack to chase you out of its territory and will not hesitate to bite you with its big and ugly rabbit teeth to better convince you to leave. And he swims fast, the bugger...

It is better to go around the place, because the ballista defines its territory from the bottom to the surface.

Beware of titan ballista! (Thailand, February 2006)
Beware of titan ballista! (Thailand, February 2006)

The area that the ballista considers its territory is inverted cone or funnel shape (the tip starting at the nest). A common mistake made by divers is to take distance from the top, when it is enough to move away while remaining at the same depth, preferably facing the beast: you swim vigorously backwards, while calmly presenting the fins. This way, if it feels like biting something, it will be the plastic of the fins, rather than the fat of the calf or a finger.

Most of the other species of triggerfish that can be found in tropical waters, such as the friendly clown triggerfish, with its white polka dot livery, are not aggressive like the titan triggerfish.

Clown triggerfish. (Thailand, February 2006)
Clown triggerfish. (Thailand, February 2006)

It already happened to me several times, during my dives in Southeast Asia, to be charged by an angry triggerfish... It is not always easy to spot a nest, which appears as a small crater in the coral debris of the substrate. The first attack is surprising and a bit scary. But the following times, we know what to expect about the behavior of this fish, and we hasten to flee as soon as possible!


In Koh Tao, in ThailandIn this area, titan triggerfish have become particularly aggressive, because of the high concentration of divers, who disturb them every day. A few years ago, a triggerfish was even nicknamed "Tyson" by the local diving instructors. The fish had, it seems, bitten the ear of a client... (like boxer Mike Tyson during a fight in 1997, which became famous since, because of this "incident").


Update. But it is not only tropical waters... The triggerfish is rampant as far as France, in the Mediterranean! Attacks and bites attributed to a common triggerfish were reported by bathers in July 2020. Read → Holidaymakers bitten by a mysterious fish in the Mediterranean Sea: the marine animal has finally been identified


  Indonesia: Bali - July 2008

  Between Two Journeys

  Malaysia: Peninsula and Borneo - July 2006

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  1. Dear Corinne,

    Marie-Ange not being around a computer for the next week, I'm managing the blog during this time.

    Now, not knowing if it accepts embedded links to a comment I have disapproved your comment linking to this article. It is not deleted, just waiting for moderation in the admin. If she wants she can post it when she comes back.

    Thank you for your understanding.


  2. No worries, Roman!

    The "link" you are talking about is not a real comment, in fact, but just a "pingback" or "automatic backlink", generated by itself as soon as you link to another blog.

    I deactivated this function on Petites Bulles d'Ailleurs, because it hinders the discussion between the users, I find, to have these false comments with extracts of a blog which made a link towards mine...

    So it's no problem for you to remove this automatic pingback, which has no other interest for Marie-Ange than to point out that I linked to A World Elsewhere. (I think she usually deletes them, because it's not the first time she and I link to articles published in the other's blog).


  3. I love the sound of the triggerfish when it eats the corals, it always amuses me. But indeed I keep my distance even if the triggerfish does not scare me. Always beware of appearances.
    You make me want to dive there all right now.

  4. However, it does not look mean this fish, colored and everything...
    Me, it's the morays that scare me!!!!!!

  5. @ Denis: The sound of the triggerfish eating the corals? "Scronch-scronch-scronch..." 😆 But I won't try to get close to it to capture that sound that amuses you, next time! And if he doesn't scare me either, the ballista, I'm like you, I'm wary of him. We don't have time to see it coming, it has already bitten. That's obvious.

    @ PhilippeB: Funny creature, the ballista... Certainly. But more because of its morals, because it's still a fairly common fish. As for its weight, no idea. The bigger ones are quite big, up to 80-90 cm long, I'd say. Must be a few good kilos. I wonder if you can eat it, the triggerfish? 😯 Happy New Year too! 🙂

    @ Helen: Yes, I assure you! The meanest fish of all, that's him. Moray eels are wise and shy damsels, in comparison. They are not spoiled by nature with their big mouths, but they are not the kind of fish that will attack you and bite you. You just have to avoid waving a finger in front of them. It intrigues them, so they think it's something to eat passing by... 😡

  6. Well, ok, thanks for the info: if I come across a triggerfish while going for a swim in the lake...(That's right, it's so hot right now.... 😕 ) I'll be careful!!!
    Biz! 8)

  7. 😕 Ch'tite question : I'm desperately trying to find info on "mating season" or "nesting" for titan triggerfish...

    I met some very nice ones who came to say "hello", while I was "slightly" afraid - that made the guide laugh. Nice, even playful...

    If there is a fish that scares me, it is the titan triggerfish (and blue stripes...)

    So I'm looking for information about when these beasts are in rut... No way to find the info (depending on the seas, no doubt - I'm looking for the maldives). Does anyone have any info?

    @PhilippeB: Apparently, yes. The triggerfish is eaten - second-hand info ...

  8. @ Jon: No idea about the "season" of the triggerfish, if there is one. I think it depends on the area, and the climate... Basic precaution, when in doubt: keep your distance, by observing the behavior of the animal.

  9. @Corinne : Yes, they are eaten in Thailand, I just saw one in the fish section of Carrefour Rama 4 in Bangkok. Indeed these teeth are quite impressive ......

  10. @ PhilippeB: Nooooo!!! No way! Ballista at Carrefour?!!! Unbelievable... Thank you for having gone to verify this amazing information on the field. I'll have an emotional thought for the triggerfish, the next time I'll meet one...

  11. Hello Corinne,

    Yes I confirm, the titan triggerfish is very aggressive, we were attacked for more than 5 minutes in Bunaken (Manado, Indonesia)... Usually, moving away a little bit by showing the fins is enough, but he did not give up until we were far enough, 10-15 meters... The following week, a diver was even bitten severely 3 times by the same titan triggerfish.

    I can also confirm that a lot of balistes are eaten! I saw some on a market in the Philippines. They cut it in pieces without the skin, and washed it with water. Why did they do that? It's a mystery.

    Have a good day.

  12. Thank you for your testimony, JF23. Not very reassuring ... Enough to encourage everyone to be cautious when a ballista emerges! Brrr.

  13. Hello,
    In Lembeh, a guide had a (small) finger bitten off by a big puffer fish. It attacked him just like that, without any apparent reason. He was furious because he is probably the only diver to have been bitten by this debonair species.
    JF23, It seems to me that the skin and entrails of the triggerfish contain toxins. In addition, the skin is thick, almost like leather.
    Corinne, I love this blog. Congratulations to you.

  14. @ Phylos: A finger puffer!!!! 😯
    Oh, dear! I'm going to be careful now. The last time I approached a puffer, I wasn't overly concerned. I stayed for long minutes under his nose, flashing him, closer and closer. He let me do it nicely. Well, I will know that you should not trust the apparent placidity of puffers (for the uninitiated: balloon fish)...

    Otherwise, I didn't know that ballista contained toxic substances. I guess to eat it, it is better to know how to prepare it properly...

    Finally, thanks for the compliments! I will try to continue in the same vein!

  15. March 2010 and I'm coming back from Maldives.
    At each snorkeling dive, I found a malevolent look in the eyes of these titan ballistas. Cornered looks, "not catholic" way of swimming. In short, they did not inspire me.
    And then, we wanted to make a nice picture by attracting the fish with some bread (not good...). And suddenly, a violent attack of the triggerfish: a quick escape in reverse, on about fifteen meters, was immediately imposed, with a strong defense thanks to the flippers. There were three of us, and it attacked us one after the other. No injuries, but nice scares.
    Moral: it is better not to irritate the ballista on the one hand and not to hang around in its area when you see it on the other hand.

  16. @Georges: Yes, the triggerfish is a territorial fish, and when it defends the area where there is its nest, it can be very aggressive. It is fast and quick, so it is better to move away when it attacks, and to present it with the fins. Where I am, at the moment, in Pulau Weh (Sumatra, Indonesia), the triggerfish are peaceful, we are not yet at the period where they make their nest, but I always watch them from the corner of my eye.

    1. Hello

      I live in Reunion Island, in St Pierre, and I regularly snorkel in the lagoon, without fins.

      There are plenty of picasso triggerfish, and I noticed a pair of titan triggerfish several times.

      Picasso triggerfish started to become aggressive in late October, and will most likely be aggressive until at least February, based on my experience as well as testimony.
      As for the titans, the ones I saw were about 30 cm long, and were not (yet) aggressive.

      The good thing about picassos is that they don't bite right away, they make an initial intimidating charge first.
      On the other hand, it is true that the more people there are in the water, the more they seem to be exasperated and charge from further away.

      Yours sincerely 8)

  17. We crossed several of them last February on koh tao nuanyuang. We slept 3 days on the island and the evening when all the tourists left the site was for us. I called it with my daughter the guitar fish because it has the volume. It broke the corals with its teeth. Fortunately, it did not pursue us but they are relatively close to the shore...I conclude that we were very see them..without being attacked.