There ARE some ways to tell when a fish is having trouble in a particular sized or shape of tank, or has outgrown his tank.
One is departure from natural behavior, failure to move from one spot, hiding during times it used to be out and about, coming out to eat only when food is offered, never or rarely foraging around, and going back into hiding after feeding when burrowing or reclusivity was not its previous habit.
Increasing tendency to crowd other fish or to move into their territory: this can include invading inappropriate territory, or short fin-flicks indicating threat.
Simple inability to maneuever well in the rockwork. Fish swims slowly, carefully, like a big careful dog in a china display.
'Fatness', ie, the fish is piling up girth but not length, which in some fishes has been demonstrated, post mortem, to include fatty accumulation in the liver, which means problems---early death being one of them.
The fish's tankmates may increasingly start disappearing---dying, or just being driven out of sight. The rate of 'strange fish disappearance' begins to thin the population in the tank.
You may also see the fish swimming at an unnatural angle, leaning, or swimming nose-high, etc.
Panicky, jerky motion or quieter fin-jerks while standing still are another sign of a fish that is feeling uneasy or cramped.
So is pacing the same route again and again.
There are other warnings, but these are the ones off the top of my head. Particularly it is hard for the stereotypical neo-hobbyist who has bought a fish and intends to 'get a bigger tank when it grows' to realize that the signs are there and it is well past time to do something. If you observe ONE of these signs: they vary with species---time to reassess.
And the motivation of a dealer wanting to sell you a tang for your 50 gallon tank---I fear may not be selfless. He may hope to sell you an 500 gallon tank next year. Don't be taken in. Marine fish offered for sale are small because of shipping constraints: their growth potential is huge. A unicorn tang can get up around 40" long. That's hip-high. Not to mention the girth. And SHAPE of tank matters: you need length above all for the larger reef fishes: and if your living room doesn't have an 8 foot wall---don't get one of the larger tangs. It's one thing to buy a larger tank. A larger house is a more serious undertaking.
If you aren't the Seattle Aquarium, don't attempt to keep a Leafy Sea Dragon, even if there's a dealer trying to sell you one. You cannot keep every fish in every tank.
One is departure from natural behavior, failure to move from one spot, hiding during times it used to be out and about, coming out to eat only when food is offered, never or rarely foraging around, and going back into hiding after feeding when burrowing or reclusivity was not its previous habit.
Increasing tendency to crowd other fish or to move into their territory: this can include invading inappropriate territory, or short fin-flicks indicating threat.
Simple inability to maneuever well in the rockwork. Fish swims slowly, carefully, like a big careful dog in a china display.
'Fatness', ie, the fish is piling up girth but not length, which in some fishes has been demonstrated, post mortem, to include fatty accumulation in the liver, which means problems---early death being one of them.
The fish's tankmates may increasingly start disappearing---dying, or just being driven out of sight. The rate of 'strange fish disappearance' begins to thin the population in the tank.
You may also see the fish swimming at an unnatural angle, leaning, or swimming nose-high, etc.
Panicky, jerky motion or quieter fin-jerks while standing still are another sign of a fish that is feeling uneasy or cramped.
So is pacing the same route again and again.
There are other warnings, but these are the ones off the top of my head. Particularly it is hard for the stereotypical neo-hobbyist who has bought a fish and intends to 'get a bigger tank when it grows' to realize that the signs are there and it is well past time to do something. If you observe ONE of these signs: they vary with species---time to reassess.
And the motivation of a dealer wanting to sell you a tang for your 50 gallon tank---I fear may not be selfless. He may hope to sell you an 500 gallon tank next year. Don't be taken in. Marine fish offered for sale are small because of shipping constraints: their growth potential is huge. A unicorn tang can get up around 40" long. That's hip-high. Not to mention the girth. And SHAPE of tank matters: you need length above all for the larger reef fishes: and if your living room doesn't have an 8 foot wall---don't get one of the larger tangs. It's one thing to buy a larger tank. A larger house is a more serious undertaking.
If you aren't the Seattle Aquarium, don't attempt to keep a Leafy Sea Dragon, even if there's a dealer trying to sell you one. You cannot keep every fish in every tank.
