ATTN: Age Old Fish Growth Myth Uncovered.....

[TCTFish]

For the longest time I always wondered about the saying "fish don't outgrow the size of their tanks". I always thought this was a myth. I mean, obviously an oscar can't be kept in a 20 gallon tank forever, but think, what does happen when fish are forced to stay in tanks with very little room for movement? Does it grow out with tail or other parts sticking out? No. Fish do not grow out of their tanks, and they do try not to outgrow them.

In an effort to continue growing in such a small environment, instead of growing outward as a fish normally does, the fish will start to change shape so it can fit in it's tank. Oscars, for example, become scrunched in body shape more so than those properly kept in appropriate size tanks. The bones of the fish are forced to become manipulated.

An extreme case of such deformities has been brought to my attention recently which inspired my conclusion to this age old fish myth. I wish I had felt better to go to the store and take a photo of this FW silver tip catfish before it was justifiably put down.

The fish was well over a foot in length, close to two feet and was raised and kept in a 20 gallon tank. How did the fish keep from out growing the tank? It's spine had grown to give a sharp deep V into the animal's back. It folded as it grew to avoid growing out of it's environment. The owner of this fish gave him to us. When placed in a 125 gallon aquarium, it was evident the animal was incapable of swimming because of this extreme deformity. It was a pathetic sight and sadly, he was put down, though with the fish's best interests in mind. His face pointed to the sky, his belly drooped on the bottom and his tail was as high as his head. A clear 90 degree angle.

I have heard of people keeping large species of fish in small tanks for years without any noticeable growth when there should be. More likely this "dwarfism" is due to poor water quality and poor nutrition.

Either way, it is cruel to attempt to keep a large species of fish in a small environment. They either end up sickly or severely deformed.

So...do fish out grow their environments? Yes, but they don't grow out of them.
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[BrianNY]

Excellent post TCTFish. I suppose it's natures way of a living organism doing it's best to adapt to an environment. Reading this, I thought of the ancient Japanese practice of binding the feet of young girls to keep them as small as possible.

 

[DeFeKt]

bump
good reading
everyone should read this

 

[verucaproduce]

This would make a great sticky!

 

[Jchillin]

Great post TCTFish - Another great reason and justification for being an AA member.

 

[AquaJoe]

Thank you for this post. I really needed to hear that.

I currently have TWO Iridescent Shark Catfish's in my TWENTY gallon aquarium.

Looks like it'll be up to 100G within the next 6 or 7 months. Thankfully both are very small as of rite now and I don't anticipate them growing to too uncomfortable of a size by the time I can get them the home they deserve.

I agree with verucaproduce that this would make a great sticky. This post scared the crap out of me. All this time I thought the iridescents would only get 'so' big in a 20 gallon then would grow when put in a bigger home. Frankly, we needed this post. My fish and me.

I feel there might be alot more "mes" out there. :|

Joe

 

[ace1uno_00]

Very Interesting. Thank you for that.

 

[greenmaji]

I agree with this wholeheartedly.. there are some fish Ive seen in pet stores that I dont think should be for sale, I cant think of a tank big enough for them.. channel catfish come to mind..

 

[Zezmo]

Channel Cats

The like 3rd fish I bought was a Blue Channel cat. My LFS swore they got no larger than 6inches. My bad of course for not researching before I bought, a lesson this fish taught me. She is of course an awsome fish, but her growth rate and appetite made her unwelcome in my community after only a couple months (er after she sucked up my GF's school of neons)(er but eating the neons made her colors even more awsome)
Anyways, I ended up having to set her up in her own tank. This fish just makes me sad, she will eventually be too large for me to handle. I have made arrangement for a friend with a large size aquarium to take her once she outgrows my space. But by all accounts, she will be too large for his tank in a couple years... then what? euthanize? I don't see release as an option (raised in an aquarium don't prepare you for life in a river) My kids think that she should be cooked up for dinner... but um, I really don't see that as an option.
All in all, she should have never been at my LFS, and certainly they should have never sold her to me. So I am afraid, that despite being an awsome fish, she is doomed to a sad ending

 

[Hara]

In a way, that really surprised me. I would have thought that in the majority of cases, the fish would die from stress induced illness instead of living long enough to beocme deformed. I wonder if this fish was the exception instead of the rule.

good post.

 

[e burna]

I'm suprised they haven't tried to breed them to look deformed yet. Hope I didn't just give someone an idea, lol.

 

[TankGirl]

I have heard of this happening with a pleco, where it's nose was at the surface, its body went straight down then bent at an angle at the substrate so it's lower half was laying horizontally. It could not get out of this position, even when moved to a larger tank.

I also thought like Hara - that the fish would die (how did this pleco eat?) before it became physically deformed. This is good info and so many people need to be aware of this case study. Thanks for posting it, TCT.

 

[greenmaji]

There is a good book about this subject its called "Tank Busters" if anyone is interested.

 

[Blucat]

bonsai fish... but in reality
thats so sad

 

[severum mama]

How sad!

Very interesting post though, thanks for sharing.

 

[Toirtis]

Excellent post. In addition, it is believed that some fish may exude a pheremone that inhibits growth if it becomes too concentrated in the water....which is why fish in smaller tanks often grow more slowly.

 

[lyquidphyre]

The concept would be considered phenotypic elasticity (if I remember my ecology correctly)

Every species mission to to stay alive and keep the species going... and to do so they slowly mutate to adapt to their surroundings... whether its due to space, predetors or resources.

My boyfriend purcahsed two kissing gouramis a year ago.. both the same size.. and the one that was more readily picked on stayed in his little castle. While the other fish grew, this guy stayed the same size so he could still fit in his castle and no one could harm him. He is perfectly healthy and seems pretty happy (he swims a lot but still likes his castle) and there is no doubt in my mind he will never grow any bigger because if he does he is "at risk".

If you look at dogs or cats that have spent their whole life in a small cage, they are significantly smaller than they should be.

It's sad, but it is also amazing how our bodies/minds work

 

[j_randall1702]

I actually had a goldfish in a ten gal when I was younger, that outgrew the tank and started to "round out" I remeber it having a lump on it's head sort of like large cichlids, it evenually ended up in a pond.

 

[Toirtis]

If you look at dogs or cats that have spent their whole life in a small cage, they are significantly smaller than they should be.

It's sad, but it is also amazing how our bodies/minds work

Although with mammals, that is usually due to poor muscle and bone growth due to lack of proper excercise (which also may play some role in certain fish-grwoth, too).

 

[lyquidphyre]

Good point Toirtis