Non-toxic cowfish?

[AydenLincoln]

I feel like this is a lie? All cowfish and boxfish are toxic and will/can nuke a tank if stressed or die right? I’ve heard good things about this company too!

 

[blaxsun]

Everything I was able to find seems to indicate the scrawled cowfish is also potentially toxic to fish, so I really don't know. Not reef safe is another aspect. Cute little guy though...

 

[AydenLincoln]

@ISpeakForTheSeas Thoughts?

 

[ISpeakForTheSeas]

Yeah, everything I can find says these guys (at least when adults) may release toxins when they’re stressed/feeling threatened. That said, these guys can also change colors and camouflage, so the toxin may be used as a last line of defense by them (meaning it’s possible that they’re less likely to release any toxin than similar species).

That said, for anyone interested, here’s my super long quote about the boxfish toxin itself, followed by some food for thought on boxfish from Jay Hemdal (both quotes are taken from the same thread):

No experience with keeping them myself, but, for boxfish specifically, these guys aren't toxic when they die, they're only toxic when alive and stressed (they have to be alive to produce the toxin, and they only produce it when stressed). The toxin they produce is a potent ichthyotoxin called Ostracitoxin or Pahutoxin (ichtythoxin meaning it's a toxin that primarily effects fish, though this toxin has been demonstrated to slowly affect a wide variety of inverts too). In small quantities, the effects may be mild as long as the toxin is promptly removed, but the effects of it on fish are irreversible (meaning the fish - if they heal from it at all - will recover over a long period of time, and they will only recover if the damage is mild and the toxin is no longer present in their environment).

When the toxin is present even at 5ppm in the water (the equivalent - if my math is right - of ~3.4ml of the toxin in a 180 gallon tank), 50% of the following species of fish died within the following times*:
Abudefduf abdominalis - 6 minutes
Acanthurus sandvicensis - 8.5 min
Kuhlia sandvicensis - 10 min
Mugil cephalus - 12.5 min
Mollienesia litpinna - 15 min
Bathygobius fuscus - 30 min

Given that the damage is irreversible and lethal even at relatively small doses (and that boxfish themselves aren't immune to the toxin, though they are more resistant to it than other fish), I'd guess it's probably not an overblown risk (though it is something you could likely try to prepare for by running carbon and having a water change and QT ready at all times).

That said, I don't know how fast these guys produce the toxin, but as long as the fish doesn't get too stressed, it should theoretically never produce enough toxin to cause an issue (though I'd constantly run carbon on the tank just to be safe).

* The study I pulled the data from:

Toxic Stress Secretions of the Boxfish Ostracion meleagris Shaw on JSTOR

Donald A. Thomson, Toxic Stress Secretions of the Boxfish Ostracion meleagris Shaw, Copeia, Vol. 1969, No. 2 (Jun. 3, 1969), pp. 335-352

www.jstor.org

I’ve kept various box fish over the years. The only time I’ve had issues with toxins were with boxfish I had just caught myself and placed in buckets on the boat.
That said, this is one of those fish that appear to do fairly well, but asking who has kept one longer than two years, not many hands in the air. The only ones I have had long term success with were temperate Australian species.

Jay

Some of the sources I checked:

https://sta.uwi.edu/fst/lifesciences/sites/default/files/lifesciences/images/Acanthostracion%20quadricornis-%20Scrawled%20Cowfish.pdf

Acanthostracion quadricornis

Scrawled Cowfish Acanthostracion quadricornis These cowfish have sturdy 'armor' plates over much of their bodies, and are generally yellowish to olive green, with dark blue to vibrant blue scrawling patterns and dark spots or splotches. They have 'horns' over their prominent eyes, and a slop

www.floridamuseum.ufl.edu

Section: Fish Library: Group: Boxfishes/Trunkfishes/Cowfishes: Species: Acanthostracion quadricornis (Scrawled Cowfish)

Marine Aquarium Library: Boxfishes/Trunkfishes/Cowfishes, Acanthostracion, Acanthostracion quadricornis

www.saltcorner.com

Acanthostracion quadricornis Scrawled cowfish

Acanthostracion quadricornisis commonly referred to as Scrawled cowfish. Difficulty in the aquarium: Only for advanced aquarists. A aquarium size of at least 2000 Liter is recommended. Toxicity: Has a poison harmful to health.

www.reeflex.net