Stunting fish

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pbecot01

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Dec 27, 2004
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McGuire AFB, NJ
Just curious... what, other then tank size, could stunt a fish?

My angelfish are a bit more then a year old. They've grown a lot... but they're still not nearly full size, and I haven't seen any noticable growth in the last six months. I feed very lightly, and was wondering if this could have caused problems... or do they still have a lot of growing left to do at this age?
 
So,thats what stunting means...it could be the red blood parrots that my dad owns and stunts the silver dollar in my dad's tank never grows any bigger.Woworz..it's been 4,5 years too lol
 
Did you do enough water changes?
 
Stunting is not caused by tank size. It appears this way because most stunted fish come from tanks that are in fact too small for an adult fish. Fish, like any living creature, produce all kinds of waste (not just ammonia). Organic acids, hormones, and a slew of stuff that has been termed DOCs (dissolved organic compounds). Removing these DOCs and nitrates is the reason we do water changes. If these toxins are allowed to build up in an aquarium they begin to affect the fish's physiology. The immune system becomes depressed (fish get sick), and the build up of growth hormones causes the fish to stop growing.

There is a belief that althought the fish stop growing on the outside, they continue to grow on the inside. Thier internal organs become more and more crowded inside a body cavity that isn't getting any bigger, and eventually the fish die. This sounds plausible, but I have not seen any real research or writing to support this (if anyone knows of any please pm me). Whether or not the "organs continue to grow" belief is true or not dosn't really matter though. If your keeping a fish in water of such poor quality that it's growth is being stunted, it's time to give up the hobby or start taking better care of your tank. I'm not aiming this comment at anyone. It's just my opinion on the matter

Ohh.....no feeding is probably not the problem. Most people overfeed their fish. A varied diet of a good dry food and several frozen foods in rotation however can't hurt.
 
Would it not also make sense, though, that some fish are just smaller than others? I mean, people come in all sorts of varying heights, and other animals like horses and dogs have varying sizes even within same-breed groups. How plausible is it that these angelfish are otherwise healthy, but, by virtue of their genetic material, are just smaller than the norm? o_o
 
I have heard of people loosing a couple of fish and leaving one "stunted" fish alone, after a little while the growth started up again and it continued to grow.
 
I do good maintanence on the tank. Usually a 40% WC a week, with a lot of plants and the like. Nitrates are undetectable when I don't supplement with flourish nitrogen.

I feed a rotating schedule of a couple different flakes, frozen blood worms, brine shrimp, and beef heart, shrimp pellets, and vegetables. I usually only feed 3-4 times a week though, so I was worried that I may have been hurting them.

Thanks for the comments.
 
With cdomestically bred fish, there can be some variation in size that is normal, but with fish that are either still wild caught or recent additions to the captive bred list, there will NOT be a huge variation in size within the species, particularly for all the schooling species. Biologically, any fish that does not grow to the average size--either smaller or large than the norm--is at a greater risk for predation. Schooling is effective protection only if all members of the school look alike--one fish that stands out for any reason is more likely to be consumed by a predator, and removed from the gene pool. For non-schooling species, there are still very strong biological motivations for meeting the norms--breeding preference being foremost. There are very few species where overall health and strength are accurately portrayed by size--it's more about color, fin condition, body mass, etc.

Any species that has been bred in captivity is being selectively bred, so there will be much more disparity in traits. The standards that created the breed no longer apply, and things like fancy guppies are the result. This applies to pretty well ALL domestic breeds--cats, dogs, pigs, cows, horses, chickens, certainly, but mollies, guppies, many cichlids (including angels), goldfish--all on the list of creatures selectively bred to be non-competitive in the wild.
 
As a child, I had a very small tank (not even sure of the volume now), with 3 common or garden goldfish. Since discovering AC, I am mortified by the conditions they were kept in, but I knew no better. Still, that's another story! :sad:

Anyway, my point is that I had these 3 fish for a couple of years (pretty good going, under the circumstances), then 2 died off. At this point, I had lost interest, and couldn't be bothered cleaning out this tank for just the one fish. My friend's parents had some goldfish in a tank (not much bigger, but probably better maintained) and offered to adopt the fish from me.

Anyway, this fish went from being just a tiddler (about an inch long, I guess) and grew into something huge in that new tank. Probably about 6 or 8 inches, and lived for 15 years. OK, so nowhere near the size/age it could have reached if it had been kept properly in the first place, but not bad for something I won at the fair.

Is it possible that a fish that is stunted, as I would have thought mine was, can 'recover' if given better environmental conditions? I would have thought that stunting was something of a one-way road, but that doesn't seem to be the case here.
 
SaraB said:
Is it possible that a fish that is stunted, as I would have thought mine was, can 'recover' if given better environmental conditions? I would have thought that stunting was something of a one-way road, but that doesn't seem to be the case here.
Click to expand...

Depends on the species. Some can recover from being kept in clean water but a small tank, as long as it doesn't continue for too long. And, some species seem to have a built in mechanism that allows them to thrive in spaces that are too small for them to attain known adult sizes without harm--as long as the water is clean! Clown loaches are probably the best known species for reaching large size, given the room, but still living for 15+ years in smaller tanks without showing neagtive impacts of stunting.

As always, IMO, it's better to plan to provide adequate space and water quality to allow the fish to attain it's normal adult size.
 
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