Your parents could have kept you I need a crib or closet your whole life as well. Do you think you would have been happy. All you need to do is consider the size most tangs will grow to when healthy. Many tangs grow to 14” when fully grown. Clearly a 55 gallon tank(closet) is not suitable!I always hear people say “you can’t keep a tang in less than 6-8’ tanks” but what’s that based off of really?
Have there been studies done on stress levels of these fish? Do we even know what stress responses are in these fish? (Do we look at brain activity? Respiration levels? Unhealthy behaviours like self harm?). Where are these studies?
The most frequent thing I hear about it is “how far they swim in the wild”. Sure. But WHY do they swim these distances in the wild? Is it for finding a mate? Evading predators? Their food is scarce or well protected by other species and they go from food spot to food spot till they get kicked out? People want to make it sound like they’re out in the ocean sightseeing travelling many kms.
During university I remember a course on Ecology and animal behaviour that went over stuff like this and given the choice most wild animals would rather stay put and be fed and protected rather than walk for days and months on end. That’s not to say there’s no minimum bounds to keep an animal healthy because there’s other variables at play than food and predation. But it is to say that you can’t really compare what happens in our tanks to what happens in the ocean. Predation is typically non existent. Territorial battles are relatively non existent. Starvation isn’t a concern. The “weather” is incredibly consistent.
Ive just never seen any good evidence that supports the idea that tangs should only be kept in x-size aquarium. But I have seen many cases of tangs being kept long term in smallish tanks (30-55gallons) and kept healthy...
I think part of the issue may come down to imagined success rates. Ie. people imagine “more tangs live longer in larger tanks than smaller tanks” which shows a correlation. However what about the person keeping the tank? Typically beginners or people not very invested will have smaller tanks. Aren’t they likely to have larger fish losses overall? Are tangs really MORE likely to die in a smaller tank than say clownfish? I’d imagine not...
TLR I’d say the smallest tank is the one which can provide a tang everything it needs to remain healthy. Has that been scientifically founded? I don’t think so. Anecdotally though I have seen and heard about tangs being healthy in tanks as small as 30gallons. I will say though a big fish in a 30 gallon tank probably looks awkward.