Keeping yellow boxfish long term

bkwonnn · Jun 27, 2025

Hi guys,

I have done my best to research yellow boxfish. I added a small one. So far it’s doing well. Seems to be eating mysis and seems very relaxed.

I was hoping to get some advice from people who have experience with these beautiful fish. More and more information is out there on keeping “hard to keep” fish. Like moorish idols, who where supposed to be very hard to keep, the succes rate of keeping them improves dramatically with the right nutrition including dietary fibres.

If people have made mistakes I can learn from, nutrition advice or other long term succes stories and advice, that would be much appreciated.

Thanks in advance

Paul B · Jun 27, 2025

Boxfish are pretty common in the sea and I usually see at least one of them on my dives. I don't remember where I took this.

But they can get large and live on small crabs, worms and other small crustaceans.

They really love live earthworms and when I kept them, besides live fiddler crabs, I fed them earthworms. They have a very thin skin over their bony plates and are really susceptible to skin afflictions like ich. Most of them really don't like captivity as they are far range swimmers in the sea as they look for food.

If it dies, remove it as soon as you can as they are filed with oxtrotoxin (spelling) which is a very toxic poison but in the 10 or so I have kept, I never had any issues with that and think the danger is overrated.

If they are underfed, you won't notice because of their bony plates, they don't get skiny like normal fish.

They are a really cool fish if you can keep them long term.

By the way. Moorish Idols are still difficult to impossible to keep for their normal lifespan.

I kept my last one for 5 years which is a dismal failure and as far as I know, no one has kept one in a "home tank" longer than about 7 years which still stinks.

Good Luck.