Yellow Boxfish – Toxic And Inspiring?

Yellow Boxfish – Toxic And Inspiring?

Yellow Boxfish Have An Evil Side

Yellow boxfish are virtually guaranteed on any Phuket scuba diving trip. Cute, quirky and very photogenic, the yellow boxfish hides a couple of surprising facts. It should be of no surprise that the yellow boxfish has some hidden survival strategies. Being bright yellow and swimming around with no discernible plan isn’t going to keep you alive very long. It’s swapped the usual fish strategy of being fast or spiky for something different.

Toxic Terrors?

Don’t cancel your Phuket scuba diving trip just yet but yellow boxfish can indeed release toxins into the surrounding water. The ocean equivalent of a skunk but with added death. It won’t harm you (unless you eat it) but can quite literally turn life belly up for any potential predators. The toxin (pahutoxin) works in a truly horrible way. The yellow boxfish releases a cloud of pain from all over its body that can burst red blood cells. You’re not going to see randomly exploding fish on your Phuket scuba diving tour (would be cool though), the toxin works by adhering to fishes gills and basically slowly strangling it to death.

Along with the toxins, the box shape is formed by bony, armour plates with holes only for fins, eyes, tail and that strange puckered mouth. So predators could lose their teeth as well as getting a mouth full of cell exploding toxins. It’s not just the yellow boxfish that has these traits. The gaudily coloured spotted boxfish can leave the same lasting impression on would be diners.

They can be extremely annoying for photographers but stressing a yellow boxfish could result in some collateral damage. It only takes one part in 10 million to asphyxiate its fishy friends. Roughly equivalent to a shot glass in an olympic size swimming pool.

Recruited By Mercedes Benz

Back in 2006, Mercedes Benz built a concept car inspired by the shape of the yellow boxfish. Even though they wisely chose not to paint it with boxfish livery, the car never made it to production. So why were Mercedes inspired by this oddball/box? Apparently the high agility and manoeuvrability of the yellow boxfish must mean its very aerodynamic and stable, apparently they were wrong… Turns out that the body is aerodynamically unstable and it’s the fin movement that corrects it all. Ah well, just a few million down the drain.

yellow boxfish inspired mercedes concept car

yellow boxfish inspired mercedes concept car

They Don’t Age Well

The incredibly cute juveniles start life as a bright yellow spotty cube but that soon changes. As they get older both males and females begin to elongate and change to a more blue/grey colour with just a hint of yellow. As Juveniles they tend to hide in reefs with plenty of get away holes, as adults they prefer more exposed rocky areas. We’d like to show you what the adult looks like but they’re just too ugly.

They grow on a diet of mainly algae with some sides of molluscs, crustaceans, small fish and sponges. The adults can reach up to 45cm and although we get plenty of juveniles on our local reefs, the adults are much more elusive. However you can find them all over the boulder strewn sites of the Similan Islands National Park.

You can find yellow boxfish on any of our Phuket scuba diving tours but they’re especially prevalent at Koh Doc Mai, Shark Point and Anemone Reef. They’re just one of the many fascinating creatures that Local Dive Thailand’s fantastic guides can show you. Join us anytime of the year for the best Phuket diving experience.

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By Justin Hartrey

I've been enjoying the incredible marine life in our oceans for over 25 years. 13 years ago I became a PADI professional, hoping to introduce as many people as possible to the incredible beauty of the seas.

Having been fortunate enough to dive all over south east and especially Thailand, I enjoy sharing my experience and passion on this blog.

Posted in Rare & Peculiar Critters on .

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