Clown loaches and stunting. Any references?

[janger]

I knew nothing about clowns. I never bought them straight away, but spoke to the LFS people who almost convinced me they'd be fine in my tank. A quick google found all those pages that say a 20 gal or larger is required. It wasn't until the fish were in the tank that I stumbled onto sites like this one.

My LFS is actually pretty good on most things. But recent events show they believe the "fish only get as big as the tank" myth. I get along well with them, and have thought of asking if I could make up some laminated cards to go on their tanks with correct information. At least I'd learn a lot more in doing so.

We actually have two LFS's in town. The other one is way more expensive and I found out one reason why. They and their supplier refuse to deal with wild-caught fish, due to habitat destruction and barbaric practices used to catch them. Now, that's a step in the right direction. If it's true that clowns are still mostly wild-caught, then I'm ashamed of even having them.

And true most people care about their pets. But some have dogs with docked tails, snub-noses, keep them tied up all day or crate them for "training" purposes. I wonder how many of them have clowns in huge tanks and think they care about the wellbeing of their pets?

Sorry, just thought I'd contribute to the debate now the threads gone off topic

[janger]

I just cannot believe that, from a site such as this one, after a few days no one can show some evidence for the proof of stunting in juvenile clowns. This is so unscientific that it borders on "urban legend". There is no way you people are going to change the minds of fish shop owners unless you can come up with proof. Sorry, but it disgraces me that people who think they care for such an interesting species of fish, all you have to say is "monkey see, monkey do".

Do you ever think this is why clowns are still being sold to people with small tanks? If you can't show the proof then forget this. I have asked again and again for the proof and all I get is "So-and-so said you need a bigger tank. Therefore you do". It's not good enough. If I took that poster in to the LFS, they'd snigger, agree to read it, and when I left the shop they'd screw it up and throw it in the bin. Oh yes, go ahead and say they shouldn't sell fish. You people are supposedly trying to change that. But from what I witness, you're not even hearing the starting gun.

Just because fish reach a huge size in the wild does not mean they do in captivity. And the reverse is also true. After finding out no one knows much at all about the biology of clown loaches, I'm wondering where the info is coming from. Practically all our information on the biology of Maccullochella peelii peelii comes from the wild. How can you say that clowns growing over a foot in length in the aquarium means they are healthy? Bigger is not always better, as they say. This is getting to the point it should be sent to Mythbusters.

Evidence please. And no videos of 12" stunted fish. I'm talking about juveniles showing signs of stunting, in say, a 30 gal tank. Like I have for almost every post in this thread.

I'm starting to get angry that a site dedicated to a species of fish seems not to be able to justify the recommendations they're making. This is b******t.

Oh, and I'm pretty much neutral on the whole topic. But I need the e-v-i-d-e-n-c-e, to help you so-called humane people make a change.

[Emma Turner]

You need to calm down a little, janger. Getting angry and swearing is not going to help. People may have been too busy to answer for the moment, but replies will come I'm sure.

I have worked in the trade for a long time and have seen first hand evidence of stunted clown loaches. At our shop, we will not sell juvenile clowns for tanks less than 4ft in length as they need space to develop properly. We have rehomed countless clown loaches for people who have bought them from elsewhere (unscrupulous dealers who don't care what size tank they go into) and which have been deformed by the stunting process. We've seen young clowns which have been recommended by other shops for 2ft tanks, which I find scandalous. These fish have been rehomed with our store and as I have said in other threads on this forum, display a very steep slope to the front of the head (which is not normal in juvenile clowns) and an out-of-proportion body. If the body is out of proportion, then it's internal organs are likely to be being compromised.

The reasons Shari lists in the original thread you highlighted are spot-on.
How many clowns do you see reaching their full potential? Not many. This is because they are sold for tanks that are way to small for them at the outset, which is when they have their fastest growth spurts. Stunting the fish at this age means they will never attain their proper adult size, which to me is cruel, unnecessary and completely avoidable.

Emma

[loachmom]

I've spent a little time reading through this article that Shari2 pointed out:

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

To me, the article seems to state that stunting is caused by a lack of food caused by over-crowding--not because the pond was too small. If that is the case, then if one performs frequent water changes and provides high quality, plentiful food, could our loaches live good lives till we could provide more room?

Does anyone else have the time to read this article and see if they came to the same conclusion?

It is an interesting article.

[janger]

Yes. I'm very sorry for my "outburst". I'm getting a little too emotional over this. And thanks Emma. I have been waiting for you to make some comments.

Ok, so the symptoms of stunting are correct. Then does that mean if none of those symptoms ever show up, the fish has not been stunted during its life? Obviously if the symptoms do show, then it's too late, since most of those symptoms require a relatively long period of impeded growth for them to be seen.

But, and this is a big but, do the fish show signs of stress before permanent damage occurs? Is there any tell-tale changes in behaviour? Is it possible to look at a tank and say "that clown is showing preliminary signs of stunting"? Are these symptoms witnessed in nature, and under what conditions? What is the diversity of body shapes in the wild, and under what conditions do they occur?

Another thing, a 2ft tank is much smaller in volume and substrate area than a 3ft tank. How old were these stunted clowns? How long had they been in the small tank? What was the water quality, feeding rate, food quality like? How many clowns were there? Was the tank overstocked?

I've spent a little time reading through this article that Shari2 pointed out:

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

Does anyone else have the time to read this article and see if they came to the same conclusions?

It is an interesting article.

Yes I have read it and came to the same conclusion as you. In fact, I have just spent 6 hours searching science publication sites for similar articles. And it does seem that over-population, competition and availability of prey are the major factors of stunting in the wild. I have found reference to a study comparing growth and mortality rates for fish in ponds and fish in tanks. I haven't found it yet but it should be a good read.

I apologise again for my previous post.

[chefkeith]

Janger- Even a team of scientist wouldn't give you the answers you want because it would take 20+ years of testing in a lab to get the EVIDENCE. They'd need to do atleast 2nd and 3rd generation studies also, so I'd wish the team of scientist good luck in breeding the clown loaches.

Do you need evidence of global warming too?

[janger]

Do you need evidence of global warming too?

Yes I do. But we already have that. IIRC, what isn't known is how much of the effects are caused by humans, and how much is due to a natural cycle.

Well many of the questions I asked in my previous post are pointed towards Emma who - and I'm assuming here - can answer them. Tank size and time spent in it, size and age of fish may hopefully all be available.

Information on growth deformities and other effects occuring in the wild should also be available as clown loaches are not rare. Obtaining information from asian scientists may be a little hard though. My government's scientific organization does not seem to have anything either. I have found an Indonesian company that exports clowns and have emailed to see if they have any information.

What Emma said about the abnormal head shape has shown up in several studies of other species, and may (more studies required) occur due to impeded growth of head cavities. Fusion of vertebrae has also been noted in studies comparing juvenile fish raised in different tank sizes. Though I couldn't find information on actual stocking densities of these studies, they were apparently very crowded. Other studies have also shown that many species bred in aquaria have a larger number of deformities compared to wild fish. Reason not known.

So I'm getting there. Slowly.

[shari2]

Janger, I realize that you are frustrated that the published 'proof' you are seeking is not forthcoming. There is anecdotal evidence galore, but the systematic scientific evaluations that provide the answers you feel you need have not yet been found. There are many such studies which have been done on food fish or wild fish populations. We are dealing with aquarium fish, and the issue is rather more complex than simply overcrowding, or poor water quality. But, I'll get back to this in a minute...

Oh yes, go ahead and say they shouldn't sell fish.

Is that what you think NCIAC is about? You think we are the PETA of the fish world?
NCIAC does NOT desire to tell any retailer they should not sell fish. What we are after is retailer responsibility and accuracy in information, not putting them out of business. It would be rather hypocritical for aquarists to be telling the retailers who provide them with their fish and aquarium supplies that they should not sell fish, don't you think?

Are these symptoms witnessed in nature, and under what conditions?

Clearly they are and if you read that article I posted you'll already know under what conditions. But let's look at part of the abstract again:

Interactions between the ecological and adaptive mechanisms of stunting are shown to be intricate: not only does the age at maturity of individuals affect their growth trajectories, but, in addition, alterations in growth conditions can result in different adaptively stable ages at maturity. We show that such adaptive responses can either alleviate or amplify stunting caused by ecological factors. Life-history adaptation may also lead to the persistence of stunting when ecological factors alone would allow for normal growth. An appreciation of the interplay between ecological and adaptive factors therefore is critical for understanding the causes and mechanisms of stunted growth.

Stunting is not a clear cut case of only resource limitation or ecological consequences. There are a number of other species specific issues which must be factored in (the 'intricate' issue).
1. Age at maturity of individuals--self explanatory. Some fish are mature at 6 months, others take many years.
2. How stunting affects individual species growth trajectories--do they grow rapidly under normal circumstances and stunting slows that process toward maturity, or are they normally slow growers, and stunting accelerates the maturation process, leading to shortened life span?
3. How do the alterations in those growth trajectories affect the 'adaptively stable' ages at maturity?
Fish, like most other organisms, will adapt to their environment. This study found that adaptive responses of fish exposed to ecological factors which lead to stunting can cause individual fish to do one of two things:
a. alleviate the stunting caused by the environmental factors to which they are exposed.
b. amplify it.
The segment above also seems to me to be saying that such adaptations may lead to continuance of stunting even after the ecological factors (such as resource limitation due to crowding, or poor water quality) have improved and conditions should 'allow for' normal growth. Meaning, if you purchase a fish that had in their 'life history' been subjected to conditions under which its 'adaptive response' led to the amplification of the stunting process you may find yourself with a small fish who fails to grow normally, even though in your tank, all the conditions should be optimal for growth of the fish.

The last sentence of the abstract bears repeating:
"An appreciation of the interplay between ecological and adaptive factors therefore is critical for understanding the causes and mechanisms of stunted growth."

It is not a simple 'this is the cause' and 'this is the cure' scenario, though I think that is what you're looking for. I'd be willing to bet that it is different for different species, and that within each of those species it will be different for individual fish.

Will keeping small, juvenile specimens of large growing fish in small, well-cared for tanks short term be a problem and lead to stunting. Personally I doubt it. I think we've all done it. That's assuming that the juvenile fish you have brought home had not been previously exposed to conditions that led to an adaptive response which was negative.
Can you keep them in that same small tank as they become adults and avoid stunting their growth? Maybe.
As the article said, some fish will adapt to their environment and that adaptation leads to alleviation of the symptoms. But in other fish the adaptive response will lead to amplification of the effect. How would you know which response your specific species/individual fish will have until you see symptoms of such stunting or the absence of it? And if it is true, as the article abstract states, that sometimes simply improving the conditions will not cause fish to resume normal growth, well, then you have a stunted fish.

Does any of this provide you with the kind of answer you're looking for? Probably not. Sorry.

I have found reference to a study comparing growth and mortality rates for fish in ponds and fish in tanks. I haven't found it yet but it should be a good read.

When you do, please post it, I'd find it interesting too.

As chefkeith said:

Even a team of scientist wouldn't give you the answers you want

The interesting thing about scientific research is that studies are designed to either prove or disprove theories. Investigation leads to conclusions on the part of one study. Another study is done by someone else to see if the results and conclusions of the first study are repeatable (peer review), and then yet another study will be designed to take those studies further or investigate another aspect of the issue that has yet to be systematically studied and the peer review process is repeated. It's a never ending process. If the study (or studies) exists which will provide you with the answer you're seeking today chances are that down the road another study will come along that may change the answers you thought you'd found through the first one.

Palaeodave posted:

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.

As I think I attempted to explain based on what the abstract above stated, it seems that the mechanism is not any one thing for all fish populations or even for all individuals within a given population. It is a complex set of interactions between environmental causes, food competition, growth rates, age at maturity, and adaptive responses in individual fish. Apparently, pirhanas have the ideal adaptive response (or at least some do). How do you determine which fish in any given fishkeepers tank will also share that response?

whatever the mechanism, or reason (or multitude of reasons )for it, 'stunting' IS NOT A MYTH. The simple fact that there are scientific studies being designed to study the phenomena means that it has been recognized as a reality. Do they know why it happens? Not entirely, but it has been seen that it does, and they are isolating causes, and the further they look the further they find themselves having to look.
The simple answer that it all comes down to water quality OR tank size, isn't true in all cases.

[chefkeith]

Going back over this thread-

Oscars will grow no matter what.

That's False.

[janger]

Are these symptoms witnessed in nature, and under what conditions?

Clearly they are and if you read that article I posted you'll already know under what conditions.

No, I don't think you're correct here. The stunting talked about in that paper is neither cruel, nor detrimental to the species studied. Well it could be, but what I mean is it does not cause the symptoms we have talked about in clowns such as deformities. The species is adapting to changes in the environment. Smaller slower growth, larger faster growth, earlier maturity etc. I never read anything in there about abnormal deformities or other health problems. Maybe I missed it?

For example, in most species larger mature individuals produce more eggs. If for some reason the majority of large fish are wiped out, the species may adapt to mature earlier so that the number of juveniles produced each year is maintained. Because of this, more energy goes into gonad formation at an early age instead of being used to increase the individuals mass. But in the name of survival, not flat heads or crooked spines. How they know to do this is anyones guess. But it has been shown that individuals are affected by others close by. And yes, other studies show that when the cause of stunting is removed the fish begin to return to their previous size.

Going back over this thread-

Oscars will grow no matter what.

That's False.

Yes it is.

[shari2]

Let's go back to the beginning:

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.

First of all, let me say that having 3, 3" clowns in a 39g community does not make you 'guilty' of any crime. As I've said on multitudes of occasions to multitudes of posters here, ultimately YOU have the right to decide what fish you choose to keep and how you keep them. You don't have to listen to me or Emma or anyone else.

You said you believe in the guidelines. By this I'm assuming you mean that they are about at the stage where in your opinion they need a larger tank or that they will in the not too distant future?

You want to prove to those who've told you that they will be fine in that size tank for the rest of their lives that they are wrong and the guidelines you believe to be true are correct. (am I understanding you correctly?)

To do so you are seeking authoritative sources for evidence that it will be detrimental to the clowns to be kept in tanks that are too small for them, yes? Sources such as photos, veterinary diagnosis, or even 'convincing' observations from the experienced hobbyists here are what you are after?

It sounds like the kind of study you really need is one designed to compare growth and development of clowns kept in say, a 39g tank from a very young age with clowns kept in say a 250g tank. Try to create conditions and select fish that are as identical as possible. Care for them meticulously over say 10 years or so, documenting and measuring their growth over time, taking pictures and making behavioral observations. At the end of the study period you will have the data you need to draw your conclusions and should be able to say one way or the other whether the size of the tank was a factor in their growth, or if stunting is a myth and clowns only grow to the size of their tank without any negative side effects.

Unfortunately, you probably won't find a responsible, experienced hobbyist here, or anywhere who has done such a study.

I wish you the best in finding other sources for your answers because I don't have them for you.

I will share with you my experience in keeping larger clowns in a 40g tank, however, I don't have measurements or any scientific data. All I have is personal observations.

At one point I had too many fish tanks...
I had been given some largish clowns by a friend from the forum who was moving, though I told him the largest tank I had was 55g. That's where they went at first. But due to personal reasons I ended up having to move them to the 40g which also had other fish in it.
It was a well planted tank, mature, sand substrate, pH about 6.5, temp at 80-82F. They received a varied diet, and regular (actually more than regular) water changes and I doubled the filtration on the tank to meet the increased bioload. I also added biomaterial from the 55 to insure the biofiltration would handle the increased load.
These were the clowns in that little 40g (and believe me, I didn't realize how little it was until I put the following fish in it:

2 8" very muscly (is that a word?) clowns
2 6" clowns
2 2-3" clowns
there were other fish in there too, but it was quite lightly stocked in my opinion. I had been moving fish around, and even taken some to the lfs to downsize the number of tanks I'd had running.

Here's my observations:

They seemed to enjoy the change from gravel to the sand substrate. The large fish bulldozed the sand regularly hunting for snails. In short order (a couple of days) there were no snails.
They were active, social and had good color for the first few weeks.
Eventually they copied the angelfish (a breeding pair) in the tank and starting with the smallest, would come to my hand for food -- well, if the food was frozen bloodworms or brine shrimp.
The largest one ran the show, and also decimated the plant life. He was closer to 9".
After a short while it was clear that the larger fish did not have enough room in the tank to ever get up to full speed. They could not 'stretch their fins' so to speak. The smaller ones seemed ok with it, but the larger 2 were becoming a bit pushy with the other fish. In my opinion with the addition of the clowns this tank was WAY overstocked. But I did my best to keep up the water parameters. I offered on this forum to give the larger ones away to anyone in the area who had a large tank. No takers...and I wasn't going to bring fish given to me by a friend to the lfs. It just seemed wrong.

This went on for a time, and then illness struck. I don't know what it was, but it affected everyone, including the angels. Lost the two largest clowns first. The angels also got sick. I was able to cure the one 6" clown and one of the 3" clowns and the angels. I still have the 6" and 3" guys. They are back in the 55 and are growing. The 6"-er is now 7" and the 3" guy is almost 4". I won't go into treatment, I don't remember everything I did.

Does this have anything to do with 'stunting'? Not really, it has more to do with overstocking and trying to keep large fish in a too-small tank. Your 3 clowns will be fine in your 39 for a while. But if they don't become stunted and do continue to grow, will you run into the problem of keeping large fish in a small tank? Yes. Will you be more successful than I? I hope so.

In any case, I'm still trying to figure out how to upgrade my 55g for the clowns that are in there right now. The 7" guy can zoom across that tank in less time than it takes to blink my eyes. My observation? It's time to get him some more swimming space...he may not be stunted, but he's crowded.

If you're looking for proof of the fact that fish which will naturally grow large should not be kept in small tanks you don't need to pin your 'proof' on stunting alone. What about water quality, quality of life, complications due to overcrowding? They are also valid reasons to house fish in appropriate size tanks. How do you determine 'appropriate'? Observe your fish. Make your own evaluations. They are your fish.

[janger]

These were the clowns in that little 40g (and believe me, I didn't realize how little it was until I put the following fish in it:

2 8" very muscly (is that a word?) clowns
2 6" clowns
2 2-3" clowns
there were other fish in there too, but it was quite lightly stocked in my opinion. I had been moving fish around, and even taken some to the lfs to downsize the number of tanks I'd had running.

Wow. I wouldn't even dream of doing that.

Your 3 clowns will be fine in your 39 for a while.

This is what I've been on about. I was told they wouldn't be fine. I have been asking why 3 inch clowns become stunted. Not whether a 3inch clown kept in a 39gal tank would become stunted in 5 years.

Does this have anything to do with 'stunting'? Not really, it has more to do with overstocking and trying to keep large fish in a too-small tank.

Did I read that correctly? Are you saying clowns over 6" long were not stunted in your 40 gal but were just overcrowded?

[Emma Turner]

Well many of the questions I asked in my previous post are pointed towards Emma who - and I'm assuming here - can answer them. Tank size and time spent in it, size and age of fish may hopefully all be available.

This is impossible, given the amount of time we've been in the trade, the amount of customers we see, and the amount of fish we rehome.

What I can say is that after coming to our shop, where I display a poster with information on how big clown loaches get (the inspiration for the LOL clown poster) underneath the tanks of small 2.75" clowns, many people who had previously shopped elsewhere realised that they were keeping their loaches in compromised conditions.

The ones with the most noticeable stunting were/are fairly small fish (3-4") and display the worryingly steeply sloped head shapes. I actually have a couple of these in my 1000 litre tank at home, who I rehomed for an elderly customer of ours, and although they may have stretched out a bit (so the head shape isn't as noticeable), they have not actually grown as fast as they should have done in that timeframe, compared to similar sized fish that have never been kept in cramped conditions. Clowns generally have their fastest growth spurts when they are small, slowing down once they get to the 6" mark.

I actually have another example of this. Years ago, we rehomed 7 clown loaches from another customer. These came home to our tank. One was only around 3", and the other 6 were all bigger 5"-6". We didn't want to split these fish up as they had been together for a time, and we felt they should all go into the same tank, even if one of them was very small compared to many of my other clowns. The customer actually told us that when they first bought their little clown loach (not from us!) they weren't told they needed a large aquarium and they weren't told they needed to be kept in groups - this they found out much later on. So this little clown was living on its own in a 2ft long tank for some years (never did find out exactly how long) until they realised that this wasn't the right way to keep a clown loach. They upgraded to a 4ft tank and got 6 more clowns to keep it company. After a while, they decided that the 4ft tank was not big enough for them, and as they couldn't go bigger, they decided they should rehome them with someone who could give them the space they needed. They came into the shop and asked if we could take them (they had seen our ethical approach to their care) so we said yes, and actually decided we'd put them in our own tank at home. Several years on, all 6 others have grown well, yet the little one, who had been kept in cramped conditions from the start has not grown at all. Not in the slightest. He/she often rests at the front of the tank during the daytime (we actually joke that the bigger fish put him/her on 'guard duty') so it has been easy to measure this fish over the years.

This is proof enough for me, and I can't see any responsible fish keeper wanting to conduct a study to see if they can replicate this. It's just not ethical to do so.

Hope this helps,

Emma

[shari2]

Wow. I wouldn't even dream of doing that.

Yes, I am guilty. Human life situations sometimes has to take precedence over fish comfort temporarily.

This is what I've been on about. I was told they wouldn't be fine. I have been asking why 3 inch clowns become stunted. Not whether a 3inch clown kept in a 39gal tank would become stunted in 5 years.

Well, we tried to explain that stunting occurs over time, especially during the younger, fast growth stages. Housing very young/small clowns in tight quarters can be asking for trouble. they grow fastest as youngsters, given good conditions.

Did I read that correctly? Are you saying clowns over 6" long were not stunted in your 40 gal but were just overcrowded?

Those clowns were already large when they went in there. They spent a couple of months there. Based on what you've read here thus far, do you think that they were stunted by their time in the 40?
If you want to keep your clowns in the 39 for a while, that's up to you. Personally, I think keeping small clowns in the largest possible quarters is best, especially since they will have to expand quarters anyway unless you start big to begin with.

[janger]

I actually have another example of this....

Hope this helps,

Yes it does. That is the sort of thing I wanted to hear. Thanks for that Emma. That would all be more convincing to the LFS.

As for studies about this, I think some were done by the aquaculture industry when researching caged culture techniques. They sometimes use stocking densities of 400, 6-inch fingerlings per cubic meter of cage, producing approximately 100 kg fish per cubic meter at harvest. So the research is very important to them.