Clown loaches and stunting. Any references?

[janger]

I did a search of this forum and found a couple of posts describing symptoms of stunting, such as this one. But does anyone have any specific references to the problems and causes of stunting? For instance, a 29gal tank is too small for clowns. But at what point, age, size etc does the fish start getting affected by it, assuming excellent water quality, filtration, peaceful tank mates etc? Or are most of the guidelines on tank size based on observation, speculation or experience?

I ask this because I'm guilty of having 3, 3inch clowns in a 39 gal community. At the moment I can't see how the tank could be affecting them given their small size. But they will be going ASAP since I believe in the guidelines. But several people still don't think there's anything wrong and are telling me to keep them. I want some evidence to prove this is detrimental to the fish. One of the people works at the LFS, and I would like to show her she is wrong because they are selling them to kids purchasing small hex tanks and stuff. But I need the evidence.

Can anyone help out with some information? Whether it be autopsy photos, vet comments, or just some convincing observations from the experienced fishkeepers here. It would be greatly appreciated.

Thanks,
Dave

[LoachOrgy]

In two years mine went from 2" to 5". I have one stuning now I think. the loach hides in the corner of this stump spot that doesn't have much space. The loach stays in there 90% of the day. I bought 4 more 2" loaches two months ago and they have already outgrown this loach. The loach is tiny but lately I have been luring him out of his hole by using algae wafers...lol

[palaeodave]

Whats the actual mechanism behind stunting? I find it all very circumstancial. Some fish like pirhanas will grow right up to the actual size of their tank should their owners be so uncaring, yet so many people talk about loaches being stunted even when in a tank 10-20 times their body lenght. I'm not saying they'd be happy, but what is phisically constraining their growth? If its a simple matter of stressed environment due to lack of space, why doesn't this happen to all fish?

[chefkeith]

The main problem is a small tank just can't provide all the needs for clown loaches. It's not very practicle either.

Small water changes would need to done more frequently. Clowns need to stretch their fins too. Clown loaches enjoy lot's of water current, so a powerhead would need to put somewhere in the tank, and the there should be lots of hiding spots for the clowns where there is little to no water current. Variation of water flow is important, and this is near impossible to do in small tanks.

Clown loaches may get stunted as soon as they are captured from their natural waters and put into polluted holding tanks. The more polluted the holding tank, the more stunted they get.

It's not much different in the quality of the air we breath.

Examples would be pollution caused by cigarette smoke or 2nd hand smoke. Like being in a car with the windows closed when someone is smoking. Then compare that to being in a large building where only one person is smoking. Size is a factor, but not a determining factor. Suppose a large building is filled with smoke, but the car is smoke free and the windows are open. In this case, being in the small car would be healthier.

[janger]

but what is phisically constraining their growth? If its a simple matter of stressed environment due to lack of space, why doesn't this happen to all fish?

Yes. This is what I need evidence of. Still no one has given any. Oscars will grow no matter what. So will Murray Cod and many other Australian natives. Are clown loaches the only fish to have their own tape measures? Where is this evidence?

Note that I'm not trying to justify having my clowns in a small tank. I want proof this is wrong though. Like I said, assuming the water conditions are good for them including lots of current, lots of hiding places, good chemistry, good food, peaceful tank mates etc, etc, etc. IMO, if a 3 inch clown was being stunted in a 39 gal tank, then a 6-7 inch clown would be stunted in a 75 gal. Maybe no one should keep clowns in anything but an olympic swimming pool? Or leave them out of the aquarium hobby altogether.

Come on, there are some very experienced fish-keepers here. Let's have some info please.

[chefkeith]

What kind of evidence would be credible anyways? Not many public studies are done on animals or fish because they may be considered cruelty.

[shari2]

Here's a scientific paper which investigates stunting in fish. It will cause you $42 to buy it...but i found the url where the paper is hosted, so...see if this helps you to understand the phenomena a bit more.

If nothing else, you'll sound smart when you use some of the scientific terminology.

http://www.iiasa.ac.at/Publications/Doc ... 99-050.pdf

[palaeodave]

I didn't have to pay a penny to see the whole article. I can't think why that would be unless my computer is remembering my athens login details and doing it for me......

If anyone wants the paper I'll happily download it and email it.

[shari2]

that's because when i first located the article it was through several of those pay per view or buy a membership scholarly sites. Found the url for a direct link to the pdf without a fee. Doesn't always work, but did this time.
it doesn't all apply, but at least we know that:
1. stunting is a real thing
2. it is commonly caused by waste buildup or overpopulation (which leads to waste buildup anyway!)
3. It can be influenced by a variety of factors such as growth rate of fish, age of maturity, and hardiness of the species.

I've been extremely frustrated in the past when trying to do research and running into huge fees for the opportunity to scan a paper just to see if the info I'm looking for will be addressed. makes me crazy so when I can get around it I feel like doing the happy dance.

Layman's (or woman's) blues, I guess.

[janger]

Looks like I have the full article too. Thanks for that shari.

After skimming the article, it seems to suggest the main factor in stunting of fish is competition for resources, ie food. However, this is for natural ecosystems. In an aquarium, usually food is not limited, so this study doesn't really hold true in our case.

But it does outline what I have always been led to believe. Stunting of fish is not necessarily a bad thing. In fact it is an adaptive mechanism that fish (and other animals) use to maintain the species. My parents have been involved in re-stocking of Australian natives here. Research is still being done into optimal stocking densities for both natural waters and the juvenile farms. But it is known that healthy stocking densities are highly dependent on the species.

After a little more research, many people believe the main contributor to stunting of fish in an aquarium is poor water quality and the toxic effects due to it. So I ask, as long as you maintain good water quality and the fish has enough space to develop, does a 2-3 inch clown really become stunted in anything less than a 75 gal?

[Keith Wolcott]

One of the resources discussed in the article is crowding and space which certainly does apply to the case of an aquarium.

[janger]

One of the resources discussed in the article is crowding and space which certainly does apply to the case of an aquarium.

Yes, as pertaining to intraspecific competition. In an aquarium they are not competing for food because there is plenty. AFAIK clowns like to be in groups, so they are not competing against one another for territory or breeding grounds. A few loaches living in a 100 gal tank, fed only a pinch of food a day would be stunted though, correct?

I still want to know why a couple of few-inch size clowns in a 30-40 gal aquarium would have their growth rate reduced or impeded. I've never heard of it in any other species. Why clowns?

[sully]

nice shari. i feel like i died and wnet to heaven. charts, graphs, and equations--oh my!

[chefkeith]

I still want to know why a couple of few-inch size clowns in a 30-40 gal aquarium would have their growth rate reduced or impeded. I've never heard of it in any other species. Why clowns?

How about goldfish. Everybody has heard of them I hope. They are greatly stunted when they are held captive in fish bowls.

[janger]

How about goldfish. Everybody has heard of them I hope. They are greatly stunted when they are held captive in fish bowls.

Because they're cramped. And produce a lot of waste.

An interesting experiment would be to have two tanks connected to the same filtration system. One a small 20-30 gal tank and the other 100 or so gal. Bare tanks. Everything equal except for tank size, including light intensity and food allotment. Get some juvenile clowns from the same batch. Put half in each tank. See what happens. If the fish in the smaller tank show considerable lack of growth compared to the others, then that would be enough to convince me. Would be interesting to find out the reasons for the differences, but that would be enough to show the LFS, I think. Has this ever been done?