Myth**Fish will grow only to the tank size"

[happygirl65]

I have been seeing a lot of posts on this board and others where people are mentioning or perpetuating the common myth that fish will grow to the size of their tank.

Lets debunk this myth guys and help out the newcomers who have been sadly misinformed.

I myself have had loads of people telling me that "It doesn't matter what kind of fish you get it will not outgrow it's tank." I have even witnessed some misinformed LFS employees passing on this misinformation to customers.

This a falsehood that needs to be corrected in our hobby.

Many of us have seen tank busters...it happens so how does a fish outgrow it's tank? Where does this idea come from?

"Fish secrete a hormone that limits their growth." but in a closed environment like our tanks we have to do water changes if we want to keep the water quality up enough that they can grow and thrive. So here we are reducing this hormone and improving water quality letting them grow larger.

What determines a fish's adult size is genetics, diet, water quality, and stress.

So if we provide a poor diet, don't do water changes and overstock the tank the fish will likely never outgrow the tank because they will be stunted perhaps even have physical deformities because of it and will eventually succumb to disease and die.

I have personally seen a bent and depressed fish that had outgrown his tank in spite of his owners best efforts to keep the water clean.

So if you want a large fish, and can buy a large enough tank...enjoy... but be aware of what you are getting yourself into. Research every fish before purchasing them. It is hard to beleive that a two inch fish will outgrow even a 100 gallon tank but it can and does happen.

 

[meegosh]

I can prove this is a myth with 100% certainty. I bought a cute little fish a while back that was marked "Synodontis Eupertus" the person at the LFS said he had one in his tank (a lie) and that it only grows 3" max. If you know about the syno, that is complete BS. I had him in my 10g tank and every month he doubled in size. He started off at under an inch and now he is well over 7" long not counting his huge tail. He went from my friends 20g tank to another friends 55g and now we are planning a new home in a 150g with cichlids.

I know he would FIT in a 10g, physically, but he would have no room to swim or stretch their humongous dorsal fins. To top it all off, he is still growing like crazy!!! I've heard 8-12" on average but some have been known to be 16"+!!! Just my 2 cents.

 

[tabbycat0282]

There is a LFS near me that has a lot of fish that were sold to them because they outgrew their tank. The employee/son (?) at the store took me and my boyfriend on a tour showing us all the fish that had outgrown their owner's tanks. Everything from catfish to pleco....pacu to jack .....all of them had been in a tank that was too small for them and some of them had the scars/deformities to prove it. Some of the signs of being a tank that was too small for them were very subtle, but some were very obvious (one pacu (the deformed one) out of 8 in a huge tank was much thicker and stubby compared to the others).

I wish there was a way to keep animals the size that we prefer without limiting their quality of life (any animal for that matter), but that is not how it works. People have to be willing to do research before they purchase any pets/fish if they want to get the most out of their experience with a healthy and happy pet/fish.

 

[Zagz]

It is sadly true that this myth is wide spread in the hobby. I give you credit for trying to debunk this myth for the good of our hobby. There is nothing humane about keeping a fish in a tank that is too small and trying to stunt their growth.

 

[Capella]

This is a great post and information everyone should realize. I observed it years ago (pre-internet) with three Angel's in a 20 gallon tank. I eventually had to re-home them. They got huge, which shocked me. Then I took the tank down...25 years go by and for all the many things I did wrong starting my current tank, this size issue was the one thing I knew I wasn't going let some FS employee fox me on. I was lucky back then and found a good home for them. My favorite real LFS has several tanks of individual huge fish in them because of the "myth".

 

[melosu58]

I agree with you HG. Do you have any info or links on what you are saying. I`ve looked for yrs and could not find any. In most cases when the fish does get to big for the tank you`ll see stress set in and then you`ll see disease, parasites and other physical problems.

 

[Innovator]

Here are a few basic links with references with in relation to stress, which is the baseline of fish disease and inhibit growth:

Stress and Fish Disease

Aquarium Fish

[WorldCat.org]=

Social stress adversely affects digestive function in subordinate cichlid fish

http://www.syndel.com/anesthetics/broodstock_health_stress_effects.html

http://www.aquanic.org/publicat/usda_rac/efs/srac/474fs.pdf

 

[happygirl65]

I was having a hard time finding anything about the elusive "hormone" that limits fish growth that I have heard so much about in talking to other hobbiests and even some LFS owners.
The stress articles listed above have excellent information suggesting the hormone response in the fish itself (and not that it is released into the water) is the culprit and that it is in response to stress for a variety of reasons. This seems to make more sense than anything I have heard or read so far.

The other link I found which is not very scientific but it puts many factors in one place and is stated a little more simply. Although it doesn't really go into hormomes it does touch on a variety of environmental factors.
How Big Will My Fish Get? - The First Tank Guide - Fish Growth and Size in a Home or Office Aquarium