Why the fuss about goldfish?

[abbysue]

I've been reading, and trying to learn more about what I already have in my current tanks...
And it seems that maybe I'm committing goldfish abuse, according to posted guidelines in terms of stocking rates of goldfish.
I don't have fancy goldfish, (single tailed), they seem to be thriving, water tests OK, I do PWC's on a semiregular basis...
A friend tells me it's because goldfish are "dirty" (I'm guessing high ammonia producers?), so they should be very lightly stocked.

It may seem odd, but does anyone have any scientific research that they can point to with regards to optimum ratios, or what the output of goldfish is?

Maybe I've just got some sort of bizarre, low output, long lived and happy goldfish.

Please don't slam me for asking the question - I'm here to learn.

Susan

 

[Cichlid Kid]

Goldfish eat ALOT. They don't have a stomach so it's a straight shot right through to the other end. At some point in time, as they mature they will suffer from being in to small of a tank. Either their organs will continue to grow after their bodies stop or ammonia will get them. I see where alot of gf owners think their stock is healthy because of their activity level, appetite etc... but the sad truth is singletailed varieties should be housed in either a pond or an enormous aquarium.
No, I don't have the scientific data to back up my opinion but i do have 30+yrs. of experience and trust me I've learned alot of it the hard way.

 

[MacDracor]

How many goldfish, what other fish, how big is the tank?
While I may not have all the sources readily available, I can tell you what experience and research have taught me.
Goldfish produce more waste, ounce of fish per ounce of fish, than almost any other commonly kept aquarium species. The common and comet varieties can reach over a foot in length, while the fancy varieties often top out at roughly 8-9 inches. They are extremely long lived with proper care. Twenty to thirty years is not uncommon, and there are reports (mostly unsubstantiated) of double or even triple that.
I am not aware of any scientific studies comparing health and longevity under different circumstances (tank size, stocking, etc). I consider this to be due to a lack of funding to conduct such a long term study on what is generally considered an ecologically and economically unimportant organism. However, there is no shortage of anecdotal evidence to support the idea that common knowledge of goldfish care (disposable, live in a bowl, good for children, short lived, small, etc) is completely wrong.
So again, tell us a bit about your current setup and perhaps we can be a bit more specific with advice or concerns.

 

[abbysue]

Goldfish eat ALOT. They don't have a stomach so it's a straight shot right through to the other end. At some point in time, as they mature they will suffer from being in to small of a tank. Either their organs will continue to grow after their bodies stop or ammonia will get them. I see where alot of gf owners think their stock is healthy because of their activity level, appetite etc... but the sad truth is singletailed varieties should be housed in either a pond or an enormous aquarium.
No, I don't have the scientific data to back up my opinion but i do have 30+yrs. of experience and trust me I've learned alot of it the hard way.

I'm curious why they would stop growing externally, if water parameters are OK? It can't be purely physical confinement...
Once again, I do check ammonia and nitrites and I'm sure that my test kit is reliable as I am currently doing a fishless cycle in a 55g tank and I'm getting all kinds of positive readings there.
Thank you for sharing your experience and opinion.

Susan

 

[abbysue]

How many goldfish, what other fish, how big is the tank?
While I may not have all the sources readily available, I can tell you what experience and research have taught me.
Goldfish produce more waste, ounce of fish per ounce of fish, than almost any other commonly kept aquarium species. The common and comet varieties can reach over a foot in length, while the fancy varieties often top out at roughly 8-9 inches. They are extremely long lived with proper care. Twenty to thirty years is not uncommon, and there are reports (mostly unsubstantiated) of double or even triple that.
I am not aware of any scientific studies comparing health and longevity under different circumstances (tank size, stocking, etc). I consider this to be due to a lack of funding to conduct such a long term study on what is generally considered an ecologically and economically unimportant organism. However, there is no shortage of anecdotal evidence to support the idea that common knowledge of goldfish care (disposable, live in a bowl, good for children, short lived, small, etc) is completely wrong.
So again, tell us a bit about your current setup and perhaps we can be a bit more specific with advice or concerns.

I have approximately 10inches of goldfish in a 20g aquarium (which was what I thought was OK before joining the AA).
Some plants, some hiding spaces - all fish seem to be growing at a moderate rate.
Water tests OK for ammonium and nitrate.
I have a HOB filter. No heater.
I feed flake food predominantly, with some mosquito larvae that I scoop out of a pond in the summer.


Thanks in advance with any insights.

Susan

 

[MacDracor]

Many many times (often in threads about tangs) I find myself wishing I had bookmarked a thread I remember reading last year. It contained both a link to, and summary of, a scholarly article about fish growth.
Essentially, this article states that as fish grow, they release a chemical signature that acts as a growth inhibitor. In the wild, this is instantly diluted by the volume of water in a lake or ocean. In areas with overpopulation, or when a body of water is temporarily cut off, it builds up in the water and serves to slow the growth of the fish species that released it until population is back to a level appropriate to the territory involved.
In aquariums of inappropriate volume, it builds up very rapidly and can inhibit skeletal growth. It is important to distinguish between growth and skeletal growth here. Internal organs continue to grow. Essentially, in a too-small tank, fish will begin to grow more slowly, and will eventually suffer skeletal deformities and internal organ crowding leading to a painful and untimely death.
The article also noted that this process begins when fish are young, and the author concluded that a juvenile fish should always be kept in a tank appropriate for its ADULT size. In other words, if a foot long adult fish requires 100 gallons, then the 3 inch juvenile of that species also requires 100 gallons.

 

[MacDracor]

10 inches of goldfish (I presume this is multiple fish) in 20 gallons, while not sufficient (see my last post and man I wish I had saved that thread!!!) is far better than many do. If they are healthy now, then I'd say you're not abusing them yet. Lol. But they really will require more room ASAP.
Couple things of note.
You're keeping cold water fish in cold water! You'd be amazed how many people don't get that concept. Well done!
Live food supplementing. Again, well done! No wonder they are doing well in a small environment. Aside from volume, it seems these goldfish are very well cared for. I like that.
It's real easy to sound critical on forums, and while I do strongly urge you to get a bigger tank, credit where credit is due.

 

[jmay33]

Wanting to follow this thread so I can refer back to it!

 

[abbysue]

Many many times (often in threads about tangs) I find myself wishing I had bookmarked a thread I remember reading last year. It contained both a link to, and summary of, a scholarly article about fish growth.
Essentially, this article states that as fish grow, they release a chemical signature that acts as a growth inhibitor. In the wild, this is instantly diluted by the volume of water in a lake or ocean. In areas with overpopulation, or when a body of water is temporarily cut off, it builds up in the water and serves to slow the growth of the fish species that released it until population is back to a level appropriate to the territory involved.
In aquariums of inappropriate volume, it builds up very rapidly and can inhibit skeletal growth. It is important to distinguish between growth and skeletal growth here. Internal organs continue to grow. Essentially, in a too-small tank, fish will begin to grow more slowly, and will eventually suffer skeletal deformities and internal organ crowding leading to a painful and untimely death.
The article also noted that this process begins when fish are young, and the author concluded that a juvenile fish should always be kept in a tank appropriate for its ADULT size. In other words, if a foot long adult fish requires 100 gallons, then the 3 inch juvenile of that species also requires 100 gallons.

Thank you so much for summarizing and explaining the feedback loop with regards to skeletal growth retardation - this does make sense to me.

Question - I'm wondering if they are all all similar to mammals in having essentially a growth plate along their bones from which elongation or growth occurs. I know that mammals, once growth plate closure has occured (either naturally or prematurely due to dammage), no further growth can happen.
I'm wondering if GF's (goldfish, not girlfriends) can start to grow again if placed in a more optimal environment (no more feedback hormones) - or if once damage is done, that is it... which would be sad for these individuals, and stunt my plans for a back yard pond!

Thanks again for your help - I may need to be looking on CraigsList for more tanks (or get out the spade and make a pond... hmmm a pond would be verrrry nice

Susan (on the look out for pond supplies, and possibly dwarf fish that don't mind a 20g tank)

 

[Cichlid Kid]

Sadly the damage is done. I had carnival gf in my younger yrs. that I've kept in 10gal. tanks. And yes they grew. I did my pwc, diet, etc... and even tried to give these fish more area after i seen the detrimental effects of me thinkin pwc will solve all.

 

[Mumma.of.two]

If stunted, a fish will not grow to its full potential but, if kept in optimal conditions, will continue to grow and thrive. These fish are more prone to health problems so proper tank maintenance and good quality foods are a must.