IRL Aquarium and Fish Q&A

[Sasha]

I had this idea today. If anyone has questions on aquariums IRL, or fish species, those of us who are knowledgeable or good at research and synthesis could answer here. It might bring a little more knowledge into the world, and be good for all of us to share in as a community-building exercise.

If this takes off, I will make regular summaries here for information so the same question isn't asked multiple times. Anything about fish, freshwater and saltwater tanks, biomes, habitats, etc is fair to ask. We might even create new fishkeepers along the way, which would be great to see.

Are fish limited in growth by the size of their tank?

Yes, with a fish in a tank that is of the wrong size, the fish will not grow beyond its limits by the tank. It's actually a really horrible situation for the fish, because they end up stunted and often in considerable distress for their short lives. They also tend to only live for a quarter to a third of their total lifespans when restricted by tank size.

Take the common goldfish, for example. The common goldfish is often sold when it is a baby, and is only a couple of inches long. But it can actually grow up to 12 inches long and can live for 40 years in the wild. However, in a tank too small for them, they are lucky to live 10 years. This is especially so if they are housed alone - as goldfish are a very sociable species.

[krishnath.dragon]

Sounds like a fun idea. I'll help out and answer what I can. Be aware however that my expertise lies with freshwater fish, not marine species.

[Harmburger]

In the game, having a tank size that isn't large enough doesn't allow the fish to grow into a larger size. Does happen in real life as well? It seems there's less restriction on the fish when it's not restricted by some programming.

Do fish (outside of active swimmers, which I assume has a real life parallel) care about the size of the tank they're in? Like the full fize panther grouper in the game is 14 and is fine in a 15 tank, but having seen some full-size grouper they're very big and it seems like the tiny aquarium size in game would be like keeping a hotdog in a ziplock of water.

[Sasha]

Yes, with a fish in a tank that is of the wrong size, the fish will not grow beyond its limits by the tank. It's actually a really horrible situation for the fish, because they end up stunted and often in considerable distress for their short lives. They also tend to only live for a quarter to a third of their total lifespans when restricted by tank size.

Take the common goldfish, for example. The common goldfish is often sold when it is a baby, and is only a couple of inches long. But it can actually grow up to 10 inches long and can live for 40 years in the wild. However, in a tank too small for them, they are lucky to live 10 years. This is especially so if they are housed alone - as goldfish are a very sociable species.

[krishnath.dragon]

Originally posted by Crow:

Yes, with a fish in a tank that is of the wrong size, the fish will not grow beyond its limits by the tank. It's actually a really horrible situation for the fish, because they end up stunted and often in considerable distress for their short lives. They also tend to only live for a quarter to a third of their total lifespans when restricted by tank size.

Take the common goldfish, for example. The common goldfish is often sold when it is a baby, and is only a couple of inches long. But it can actually grow up to 10 inches long and can live for 40 years in the wild. However, in a tank too small for them, they are lucky to live 10 years. This is especially so if they are housed alone - as goldfish are a very sociable species.

The tank size thing is a myth. As in not true at all. Once the fish gets to large for the tank, it dies from ammonia/nitrate poisoning. The growth of the fish is not impeded by tank size.

And goldfish require huge tanks to be cared for properly. As in 125 US gallons or more. Unless you have one of the fancy breeds like fantails. For a couple of those a 50 US gallon tank would suffice, as they do to breeding grow considerably smaller than regular goldfish and comets. But yes, goldfish are pretty sociable with other similarly sized species, and should ideally be kept in at least a trio. But they are not a true schooling species. They can be kept alone, provided the tank houses other similarly sized temperate climate freshwater fish. Do not keep goldfish with anything less than about a third of its size, as the goldfish will try and eat it. Goldfish also require better filtration than most other temperate freshwater species, but that is mainly because they poop a lot.
Still, goldfish, including fancy breeds, are a good "starter" fish for people new to the hobby, provided you have the required space for a large enough tank.

[Sasha]

Overconfinement of fish (too small of a tank) has been shown to negatively impact corticol response, which in turn, inhibits total growth rate from constant stress-related pressure on each individual fish. Across all animal species, suppressed cortical response always leads to inhibition of overall growth. The actual rate of growth inhibition is largely unknown, however, the fact remains that overconfinement leads to stunted growth to some degree.

Here is a link to one such study on fish.

https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1095-8649.1987.tb05761.x

[krishnath.dragon]

Originally posted by Crow:

Overconfinement of fish (too small of a tank) has been shown to negatively impact corticol response, which in turn, inhibits total growth rate from constant stress-related pressure on each individual fish. Across all animal species, suppressed cortical response always leads to inhibition of overall growth. The actual rate of growth inhibition is largely unknown, however, the fact remains that overconfinement leads to stunted growth to some degree.

Here is a link to one such study on fish.

https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1095-8649.1987.tb05761.x

Good to know.
However, the literature I have read on the subject that is more recent than that study (including Practical Fishkeeping Magazine) have stated that it is false, which is where I got my information on the subject from.
However, we can both agree upon that keeping fish in to small of a tank is a very bad idea. :)