Does fish growth get stunted in an aquarium?

[vpierce3]

if you believe differences displayed by animals in the Galapagos may have been generated within a single animal lifetime by adapting each single animal to the local conditions, as opposed to adaptation over many generations by natural selection, then we do not have a shared vision of the natural world and I’m not going to waste REEF2REEF readers time trying to convince you.

Once again, I didn’t say those things happened in one lifetime. How many times do I need to make that clear? Please don’t put words in my mouth.
It’s an illustration that change happens. Good grief.

 

[ISpeakForTheSeas]

Interested in offering the best diet to promote healthy , long lived fish. You mentioned not all aquarium food being adequate for stress free fish. I am an 18 month newby, my husband is the scientist. Loving advice.

From the foods I've looked at, I'd recommend LRS Reef Frenzy (or Fertility Frenzy, if you can get it) and the Hikari Mega Marine line of foods - these are frozen foods (so they're relatively expensive), but you likely won't find better. For pellets, TDO Chroma Boost and NLS are the best I've seen - these are good, but not as good as the frozen:

From what I’ve seen, most marine species need a ton of protein (~60%; anything over 50% is probably decent, anything less then 50% and I would consider it to need supplemental protein) and relatively little fat (~10-15%) to get into peak physical condition (i.e. breeding condition), but the protein and fat contents alone aren’t enough to make a food healthy, as they don’t guarantee the food has all of the right vitamins, minerals, fatty acid profiles, etc. So, going with a food that has a wide range of ingredients in it is a relatively safe way of ensuring proper nutrition beyond just the protein and fat.

As far as pellet foods go, NLS and TDO seem to be the best (at least out of the ones I’ve looked at), but even these aren’t quite (IMO) as good as the LRS line.

I'm actually quite impressed by Hikari's Mega Marine line there; I haven't looked at that line in depth before, but it says it has a 75% dry protein content and - depending on the specific blend in the line (regular, angel, and algae) - a 10-15% dry fat content with solid/good ingredients. The only thing that I see that I wish they had in the mix is some kind of fish (LRS Reef Frenzy has Ocean Perch and Whitefish, for example) and, for the algae blend, some kind of bivalve or two. For comparison, LRS Reef Frenzy - according to their lab test results on their site - has 59.1% dry protein and 12.7% dry fat.

With regards to the moisture and protein content, when looking at foods for pets (fish, cats, dogs, etc.), it's a good idea to look at the dry matter basis of the guaranteed analysis. To state it simply, frozen foods and wet foods show super low protein and fat contents on their guaranteed analysis labels when compared to dry foods - this isn't because they're lower quality or less healthy, it's just that they have more moisture in the mix. To compare apples to apples protein and fat of frozen/wet vs dry foods, you take the dry matter basis of each factor (protein on its own and fat on its own once you've accounted for moisture).

For example, San Francisco Bay Brand Frozen Spirulina Brine Shrimp lists the following guaranteed analysis:
Crude Protein (Min): 3.7%
Crude Fat (Min): 1.2%
Crude Fiber (Max): 1.6%
Moisture (Max): 94.8%
Ash (Max): 0.2%
Phosphorus (Min): 0.1%

Looks very not nutritious. But, when you account for the moisture by taking the dry matter basis, you realize that that 3.7% protein is 3.7 out of 5.2 (the actual amount of food in the pack; i.e. the percent of the food that isn't moisture like the water used to hold the frozen food together or to keep the meat in the cat food can fresh). So, looking at the dry matter basis, 3.7/5.2 = 0.71 (rounded for simplicity's sake) - times this by 100 to get the percentage and you get a dry matter basis of 71% Crude Protein content. So, while it looks unhealthy at first glance, when you look at just the food in the food packet and not the moisture plus the food, you find out that the food is actually fairly healthy.

Because of this, a lot of frozen/wet pet foods look worthless at first glance, but some of them are actually top of the line foods when compared to dry foods this way. The only real downside of frozen/wet foods is that - because of the high moisture content - you might not always be getting as much food pound for pound as buying dry (i.e. one lb of dry food is going to have a lot more actual food in the container than one lb of frozen/wet food because of the lower moisture content). This really just means that frozen/wet foods are generally more expensive.

TLDR: Frozen/wet pet foods look unhealthy, but, accounting for moisture, they're usually high quality. They're just expensive too.

 

[Randy Holmes-Farley]

Once again, I didn’t say those things happened in one lifetime. How many times do I need to make that clear? Please don’t put words in my mouth.
It’s an illustration that change happens. Good grief.

If it doesn’t happen in one lifetime, then how is it relevant to fish in a tank that are frequently wild caught fish?

Those are entirely different effects.

Do you believe it only applies to captive bred fish, which have been living in aquaria for hundreds or thousands of generations?

 

[vpierce3]

If it doesn’t happen in one lifetime, then how is it relevant to fish in a tank that are frequently wild caught fish?

Those are entirely different effects.

Do you believe it only applies to captive bred fish, which have been living in aquaria for hundreds or thousands of generations?

I suggest you just let it go…..

 

[vpierce3]

If it doesn’t happen in one lifetime, then how is it relevant to fish in a tank that are frequently wild caught fish?

Those are entirely different effects.

Do you believe it only applies to captive bred fish, which have been living in aquaria for hundreds or thousands of generations?

Again….stop putting words in my mouth. Stop asserting what my reasoning was.
I also don’t appreciate the sarcasm. Have a nice day. Live long and prosper.

 

[Randy Holmes-Farley]

I suggest you just let it go…..

Ok, I stand by my comment that it is an inappropriate analogy, but if you do not keep pushing the idea that it is, then I am happy to let it go.

 

[Randy Holmes-Farley]

Again….stop putting words in my mouth. Stop asserting what my reasoning was.
I also don’t appreciate the sarcasm. Have a nice day. Live long and prosper.

I did none of those things and did not use sarcasm here, although I often do.

 

[vpierce3]

Ok, I stand by my comment that it is an inappropriate analogy, but if you do not keep pushing the idea that it is, then I am happy to let it go.

You’re not the analogy police. Nor do I need someone to engage in dogmatic review of my comments.
And yes, you did employ sarcasm. Not appreciated.

 

[Bruce Burnett]

I think you can look at many things for fish growth. More swimming room, more active fish. Larger tank means more food on rocks and sand. Most larger tanks are not stocked as dense. Also I find the feeding habits of some tank owners lacking. When I read where people only feed one cube of frozen food every couple of days and pellets once a day in their tank, I can't wonder if their fish are starving. I feed my tank 3-4 times a day.

 

[Randy Holmes-Farley]

You’re not the analogy police. Nor do I need someone to engage in dogmatic review of my comments.
And yes, you did employ sarcasm. Not appreciated.

The very fact that you think what I wrote was sarcasm implies that you do not understand what is wrong with your analogy.

I’m not the analogy policy. Much broader mandate. I am the accuracy police.

 

[vpierce3]

The very fact that you think what I wrote was sarcasm implies that you do not understand what is wrong with your analogy.

I’m not the analogy policy. Much broader mandate. I am the accuracy police.

Yeah, ok, whatever.

 

[Randy Holmes-Farley]

it might be helpful for this discussion for us to generate a list of possible reasons that some fish may be smaller in an aquarium than in the open ocean. Folks should add to this as they think warranted.

1. A chemical effect from something that accumulates (or is missing) in the water.

2. A nutritional effect of some sort. Could be missing nutrition, spacing of meals vs continuous picking, too much of some dietary ingredient, etc.

3. A physical exercise effect.

4. A biological effect driven by the psychology of being in a small space.

5. A biological effect of being forced into close proximity with other fish species.

What else?

 

[blazn]

I have a Hippo tang which was in a 90 gal for a couple years and due to a seal leak, had to downsize into a 40B. At that time, the Hippo was approx. 3.5" in length and remained in the 40B for 3 years, until it was upgraded into a 120 gal. Although very healthy, the Hippo had not visibly increased in size in the 3 years it was in the 40B. It's now been in the 120 gal for almost 2 years now and has increased approx. 50% in size since it was moved into the 120 gal. I primarily fed LRS Reef Frenzy during the entire time (40B & 120) and there was plenty for it to graze on when it was in the 40B. I'm convinced that the smaller environment of the 40B definitely slowed down its growth rate.

 

[HankstankXXL750]

Thanks. This is the kind of info I was hoping to find out. I am curious whether there is any concrete evidence that a fish raised in a tank will not grow to its full potential size and why that may be. Also curious if this has any health implications for the fish itself.

I will chime in here. I just started reading so this might have already been said. When I first got an aquarium I was in grade school and got guppies etc in a 10 gallon tank.
However later in life I got into saltwater. At the time I was told that freshwater fish are less likely to outgrow their tanks in nature they may reside in different conditions and space availability. (I think this would account for what was said about Koi and hormones) But that with saltwater fish you should plan for them to reach full size. This was explained to me that with the vast size of the ocean and seas marine fish never developed a need to restrict their size.

However it is fairly well documented that many saltwater fish do not reach their wild size in captivity. IMO this is due to a number of things.

One, even those of us who provide a varied diet are probably not replicating what the fish invests in the wild.

Two, even though I’m sure there are time when marine fish cannot capture everything the wish to eat in the ocean there is an unending supply. So even if they don’t eat today, they will tomorrow or later today.

Three, in captivity and in the hobby we are often encouraged to limit the amount we feed. No more than they can consume in 1 minute. Make sure there are no left overs. If you over feed you will have nutrient problems, etc.

I for one am not good at limiting feeding. I do try to feed around the same amount each day, I turn off all circulation pumps and greatly reduce my circulation flow so that more if the foods I feed vs them being absorbed or lost in the holes etc in the rock.

Especially in my predator tanks I feed to over feed as I don’t want them to feel they have to eat someone else and I have some that rely on food reaching the sand bed like my marbles Cat Shark. A fair amount of krill, silversides and shrimp end up on the sand in the feeding area, but when I return 10 minutes later it is gone.

in the 80-90s my cousin and I both had tanks and he was a careful feeder and I was not so much. My fish always grew larger than his of the same species.

That's my two cents worth.

 

[Jay Hemdal]

I have the opposite experience.Fish look small to me in the tank but huge when I net them and take them out of the water.

You may be subconsciously adjusting even more than I do - the water does magnify things by about 30%. Last night, we had a full moon. When it was on the horizon, my wife said, wow, it's huge! I showed her the trick where you hold a quarter up to cover the moon, and then do it again when it is higher in the sky - visually, it doesn't look nearly as impressive when it is higher in the sky, but the quarter showed her it was the same size.

Jay

 

[\m/reefsnmetal\m/]

If it doesn’t happen in one lifetime, then how is it relevant to fish in a tank that are frequently wild caught fish?

Those are entirely different effects.

Do you believe it only applies to captive bred fish, which have been living in aquaria for hundreds or thousands of generations?

I definitely think it's plausible to have genetic modifications develop with captive bred marine fish considering how many are in the market. But I wouldn't pretend to know what they are aside from selective traits bred in clowns. I also don't think adding the variable of captive bred vs wild caught would clear up the discussion.

 

[Randy Holmes-Farley]

I definitely think it's plausible to have genetic modifications develop with captive bred marine fish considering how many are in the market. But I wouldn't pretend to know what they are aside from selective traits bred in clowns. I also don't think adding the variable of captive bred vs wild caught would clear up the discussion.

I don’t doubt that either. Breeders always select traits they like and small cute fish might be preferred by some.

 

[Fredinva]

1. A chemical effect from something that accumulates (or is missing) in the water.

2. A nutritional effect of some sort. Could be missing nutrition, spacing of meals vs continuous picking, too much of some dietary ingredient, etc.

Randy,
I believe your 2 listed items here have more bearing than the remaining three.
Back in the 70s, i was very strong into breeding African Cichlids. That was the new rage back then!
I had even obtained some wild pairs, (or trios) direct from Lake Malawi.
Anyway my rearing tanks for the mbuna fry were either 20 or 30 gallon aquariums depending on the number of fry released. My feeding schedule was the same for all fish. I tried to change 25% of my rearing tank water weekly. My water change schedule most always affected the more desirable species, to a degree. I don't have any hardcore data, but my many observations, I do believe, tended to substantiate the obvious. Those fish which had received the most consistent water changes had grown larger and quicker than those which were semi neglected. Thus, your Item #1 above, carries a lot weight in my mind. I believe the theory would hold true for both fresh and salt water fish.

 

[Jacked Reefer]

Randy,
I believe your 2 listed items here have more bearing than the remaining three.
Back in the 70s, i was very strong into breeding African Cichlids. That was the new rage back then!
I had even obtained some wild pairs, (or trios) direct from Lake Malawi.
Anyway my rearing tanks for the mbuna fry were either 20 or 30 gallon aquariums depending on the number of fry released. My feeding schedule was the same for all fish. I tried to change 25% of my rearing tank water weekly. My water change schedule most always affected the more desirable species, to a degree. I don't have any hardcore data, but my many observations, I do believe, tended to substantiate the obvious. Those fish which had received the most consistent water changes had grown larger and quicker than those which were semi neglected. Thus, your Item #1 above, carries a lot weight in my mind. I believe the theory would hold true for both fresh and salt water fish.

Even though I know hormones are ruled out for saltwater fish, and would assume they would be for fish from large, permanent bodies of water (such as cichlids). I actually do believe i read somewhere that high nitrates and phosphate could possibly impact growth and even the metabolism of some nutrients. I would image less water changes could also strip out minerals and metals required for skeletal and muscular development. Perhaps people see these effects and claim “hormones”. While perhaps it is limiting factors rather than a self imposed cap.

 

[WestMI-Reefer]

Randy,
I believe your 2 listed items here have more bearing than the remaining three.
Back in the 70s, i was very strong into breeding African Cichlids. That was the new rage back then!
I had even obtained some wild pairs, (or trios) direct from Lake Malawi.
Anyway my rearing tanks for the mbuna fry were either 20 or 30 gallon aquariums depending on the number of fry released. My feeding schedule was the same for all fish. I tried to change 25% of my rearing tank water weekly. My water change schedule most always affected the more desirable species, to a degree. I don't have any hardcore data, but my many observations, I do believe, tended to substantiate the obvious. Those fish which had received the most consistent water changes had grown larger and quicker than those which were semi neglected. Thus, your Item #1 above, carries a lot weight in my mind. I believe the theory would hold true for both fresh and salt water fish.

I’ve observed similar effects with captive bred discus (cichlid family). The largest one will keep the others smaller, separate and they grow. I stated something about inhibiting hormones possibly being in all fish earlier but Randy shot that idea down because it wouldn’t make sense for marine fish, in the Ocean, which made sense to me. Too large of an environment to have any effect. However, if I applied that same idea to humans (or any animal), none of our hormones/pheromones should be having any effect either? Could it be localized in concentrations that they inhabit? I don’t know, but I like this thread!