Does tank size limit marine fish growth

[John Roehrig]

I had such good replies to my question on the Passer angelfish, let me try this one.

When I kept freshwater fish I was always told by the people at the LFS that the ultimate size of these fish was limited by the size of their tank.

My new LFS tells me that marine fish have no such limitation - essentially demonstrating non-restricted growth - regardless of the tank.

I kept an Emporer angel - that I grew from a baby the size of a quarter - and a Powder blue tang in a 58 gallon tank for 10 years. When the Emporer expired this year, she was about 8 inches long. The PBT is about 6 inches long. I also kept a Clown Trigger in a 60 gallon hex tank for 10 years. He was about 6 inches when I sold him back to a LFS this year.

So what's the truth. According to what I have read here, these tanks are much too small for these fish, and after 10 years I should have had behemoth fish - but I don't/didn't. Is this an example of size limitation due to tank size?

Thanks,

John

[fishy&co]

Oh my god... no offence but to me a 8 inch fish is a behemith of a fish especially in a 58 gallon tank. As too whether fish will grow to the size of the tank, i think its more thegrowth speed depending on the tank size. That same angel may have easily been 16 inches in a 500 gall setup.

[koj11]

Any fish will show limited growth in relation to their tank size to some degree.

[billsreef]

Limited growth does not equal healthy fish. Often fish that are stunted in growth due to being kept in too small a tank exhibit problems such as stunted life spans. This is true for FW fish as well. Out of curiosity, how old was that emperor?

[Triggeraddict]

When big fish are placed in small tanks, they will originally grow to the size that the tank will allow for ammonia, nitrite, and nitrate production, and because of all these factors, fish get stunted in small tanks. But if one were to keep these fish in large quarters with good water quality they will grow close to their max size. Currently I have 2 Queen Triggers and when I bought them almost one year ago (one in mid december and the other in mid Jan) the december one was an inch when I got her and the other was 2 inches well now they are both well over 6 inches in length. They grew 4-5 inches in less than a year. I would expect them to make seven by mid january. They are kept in a 200g tank with several other triggers (not recommended) but they do great and thus far they are the most peaceful Queens I have seen for their size. So tank size does have a huge impact on how quickly they will grow. Now say you took your Emperor and had moved her to a 125 gallon she would grow a bit more but never anywhere close to what her potential was.
BTW, the MYTH that fish grow to the size of their tank has long been proven false, they will grow to the size that water quality will allow before they are stunted. Some people will say look my fish grew to adult size when they are talking about a Clown Loach that is 4 inches that was housed in a 20g when the adult size is a foot. Back when I was working at our local fish store I would try and change peoples views on how growth rate works, and it worked with some people but most no. The perfect example is I was helping this woman that had a 20 long and the tank contained a 2 foot Snowflake Moray, Yellow Tang, Huma Trigger, Dwarf Lion and she tried adding a Copperband Butterfly and wondered why it died. Hmmmm. So I told her she needed to upgrade immediatly or risk loosing the rest of her fish so she decided to upgrade to a 46 which was better but not great. I don't have the end of the story since the fish store shut down and haven't seen her since. So anyway, just proves a lot of misinformed hobbists are still out there but hopefully they will change soon. Anyway, hope this helps out.

[John Roehrig]

The Emporer was 10 years old. Besides the 10 yo PBT that I still have and the 10 yo Clown Trigger that I sold, I also have a Domino Damsel (one of those original starter fish!) that is about 11 years old. All of these fish were/are in great shape. The PBT and Emporer were alone in the 58 gallon, and the Clown and Domino were alone in the 60 gallon.

One of the reasons I was interested in this answer is the conflicting information about fish size and appropriate gallonage. For example, in Scott Micheal's book, he recommends that many fish, including large angels, triggers, and tangs, can be kept in 100 gallon tanks or less. However, if you read many of the postings on this forum it seems if you don't have a 200 gallon tank all you should keep are small fish.

I guess my experience doesn't bear out that conclusion. Right now in my 100 gallon I have the PBT, a smaller blue throat trigger, a maroon clown, a long-nosed hawk, and two small yellow-tailed blue damsels. The Domino is keeping the 58 gallon filter alive as a quarantine tank. Based on my experience with the Emporer I would like to finish the stocking with a large angel. Based on this stocking profile I do not want an angel that is too shy (e.g., Navarchus, Blue-faced, Annularis, or Asfur). This leaves me with more aggressive angels to choose from (e.g., queen, Passer, french, emporer, etc.) but the recommendd tank size makes me hesitent.

Thanks to all again for the for the interesting insight.

John

[ChasingPuck]

Here's an interesting story for you. A lady turned in two 10 inch oscars recently. These were large fish, in good shape, though slightly stunted for their age (over 6 years). She'd kept them in a 10 gallon tank, with daily 50% water changes. So, great water quality, but tiny tank. The fish still got to a respectable size, but ultimately were stunted by the size of the tank.

Water quality does more to improve health than any other factor, followed closely by food. However, a small tank is still a restriction and should be avoided if possible, especially if you can't provide exceptional water quality.

[billsreef]

Pomacanthus angels have life captive life spans reported of over 20 years.

6 year old Oscar's at a mere 10 inches is more than slightly stunted.

My favortite analogy for people trying justify potentialy large fish in small tanks, using that old wive's tale, is to ask them if they think it would work out so well if they put thier small children in small boxes and expect them not to grow Usually works every time to get the point accross

[ChasingPuck]

I wasn't saying it was right to do. However, you should agree that the fact that the fish got to 10 inches was impressive, considering the size of the tank they were in. Certainly not something I would advise anyone to try.

However--the comparison of any mammal to any fish is completely ridiculous. Try not feeding your cat for 2 weeks--you either won't have a cat anymore, or you won't have anymore fish. Healthy fish, in an appropriate environment, can handily live for 2 weeks and more without eating.

[billsreef]

I'm impressed with the fishes ability to survive improper conditions, not that someone would try

BTW fish going longer than 2 weeks without food often end up with problems that ultimately kill them. One of the many problems in the supply chain facing this industry

[Bayliner]

I asked the same question in this thread.

http://archive.reefcentral.com/forum...hreadid=244012


Hope it helps
Cam

[ChasingPuck]

Agreed--it depends on the species of fish. But, comparing fish to mammals is less accurate than comparing different kinds of fish. Herbivores typically suffer more from starvation than predators, as their intestinal bacterial populations die off during starvation and often don't recover. Of course, this is why it's a good idea to encourage some algae growth in tanks with herbivores, along with feeding them more frequently than one would feed an adult predator.

[Mad Scientist]

Poor diet is another way to stunt growth. Anyway you can think of to provide poor conditions will probably prevent a fish from reaching is max size.

Now I suppose that PBT and emperor kept in a 58gal for 10 years had great colors too??? Undersized, poorly colored fish that adapt just enough to survive are what you get when you keep big fish, but, you don't want to spend the cash to get the proper setup.

A CT in a 60hex for 10years? I really hope this thread is a troll. How about some pics to verfiy the condition of these fish?

[M.Dandaneau]

Actually, this thread, and some others that I've read DO raise some interesting points.
In at least some cases, certain freshwater fish are known to give off a chemical that seems to limit growth in a specific environment, along with available food, water parameters and such, and I mean in the wild as well as in aquariums.
On the other hand, some species are actually known to get LARGER in captivity than in the wild, quite likely by better food than that which they are able to obtain in their native environment.
The marine hobby as a whole is still actually in its infancy, as far as home hobbyists are concerned, with the vast majority of life span information and such often obtained from huge public aquariums, conditions that most of us could never hope to emulate.
I suspect the final answer to the question of expected captive sizes is still being written by folks such as we here at Reef Central, and variations between wild size, healthy captive size and stunted size will end up being a compromise that is only now becoming available as more and more people communicate their experiences.

[John Roehrig]

By troll I suspect you mean that I made this up. Quite frankly I don't have the time for such nonsense, and I do not appreciate your implications.

I guess that's why you have your nickname - "MAD" scientist?.

I have had some pictures through the years, although I suspect if I post them you won't believe them! Be that as it may, I'd be glad to try and find them.

To everybody else, thanks for the constructive comments.

[John Roehrig]

Found a pic of the Emporer and PBT (back-end) and will try and post.

[fishy&co]

I dont doubt that the fish lived in that tank but to me those fish were too big for that tank and it stunted their growth but really the fish would have been far better off it had started to stunt itself the moment it was placed in the tank at 1 inch the size of a nickel. Those fish couldnt swim more than 6 body lengths and i wonder how long that took them. You should be hesitant about adding either a queen, french, emperor or passer to your 100 gall tank already with two large growing fish in it. It will only be a matter of months before anyone of those angels can only 6 swim 6 body lengths down then back then down then back then down lord help them if they live for 20 years. Sorry for being brutal in my oppinion buts thats what it is.

[John Roehrig]

Thanks for the opinion - that was the point of my post.

There have been many posts on "stunted growth," and I suppose this simply means that indeed fish size is regulated to a degree by the size of the tank.

That being said. do we know what scientifically determined physiological difficulties "stunted growth" may cause - other than a smaller fish? These fish always seemed "happy and healthy" to me. The PBT still does.

Thanks again.

[John Roehrig]

Cam,

Thanks for the link to your thread. The article referred to was quite interesting and makes sense. Perhaps my success with these three fish was, in fact, due to the low fish numbers I had in each tank.

[Mad Scientist]

Originally posted by M.Dandaneau
Actually, this thread, and some others that I've read DO raise some interesting points.
In at least some cases, certain freshwater fish are known to give off a chemical that seems to limit growth in a specific environment, along with available food, water parameters and such, and I mean in the wild as well as in aquariums.

Many FW release a chemical simply known as JH (juvinile hormone) that is suspected of slowing growth and development. When I worked in a reasearch lab, we would do massive water changes even though are parameters were perfect for this reason.

But, I think the reason why small tanks stunt growth with marine species is much more mundane: cramped conditions lead to chronic elevations of stress hormones (steriods) and depression of growth hormone, leading to small fish. These fish are more suceptible to infection, show poor colors, and probably are barely fertile.

It's really sad the conditions under which some people choose to keep their fish and this thread is a prime example. We can argue all day about the borderline cases, but, anyone who has ever owned a CT or seen one in the wild knows that this beautiful fish doesn't deserve to be kept in a 58gal hex tank for 10 years.

[M.Dandaneau]

Mad, I tend to agree about a 58 gal. hex.....a 5 foot, 100 gal. tank would have been highly preferable, but alas, this is Monday (Tuesday, now? ) quarterbacking and it obviously wasn't done out of malice or lack of caring.
This, at least to my mind, does bring up another question though......in cases where the fish are stunted solely by a smaller tank and NOT crowded into maddening circumstances, just how severely are they damaged?
I've seen cases where fish are pampered and spoiled, not harassed by other tankmates, and other than being housed in confined quarters, have had far less stress than any wild fish subject to normal predation that appear not only healthy, but actually happy and affectionate.
I once had a startling thought...to 2nd and 3rd generation fish that I'd bred and reared, I was God and these fish had no inkling of any other existence, thus appeared far happier than some of their wild cousins being stalked by pickerel, pike cichlids, etc.
I'm not passing judgement here, just tossing out food for thought, both pro and con...obviously, many fish will respond well to a lot of room.
John Roehrig, I'm certain that Mad wasn't targeting, harassing or implying anything about you individually......those of us who haunt these halls with some regularity do indeed see many "trollers" and differentiating between someone asking serious, thoughtful questions and someone out to start yet another hubub can be difficult.
It's sometimes frustrating to try and offer helpful advice only to have it turn out that you have been directing information to someone who could care less, or even worse, to someone who is simply looking for someone to agree with them to justify an obviously bad or stupid situation.

[Mad Scientist]

Originally posted by M.Dandaneau
This, at least to my mind, does bring up another question though......in cases where the fish are stunted solely by a smaller tank and NOT crowded into maddening circumstances, just how severely are they damaged?
I've seen cases where fish are pampered and spoiled, not harassed by other tankmates, and other than being housed in confined quarters, have had far less stress than any wild fish subject to normal predation that appear not only healthy, but actually happy and affectionate.

I think it depends on the species. What fish have you seen that have done well (aside from being small) in small tanks? Lets use as our defintion of "small" as 1/2 the size reccommeded by Scott Michaels.

I feel bad for jumping all over John Roehrig, but, it seems like not only on the board, but, in RL, so many people keep fish in setup ways too small for the fish. I'd rather hear about a PBT in a a 200gal than a 60gal. Although wild fish are no doubt subject to many natural soruces of stess, most wild fish are much more robust (color, size, muscle) than their captive counterparts. For me I strive to have my fish thrive, if I see severly stunted growth/developemnt, that's telling that something isn't right.

[M.Dandaneau]

Mad, I agree that in the marine hobby bigger is always better, when possible, but some things are also inescapable.
First off, captive specimens have been removed from the wild gene pool, thus survival of the fittest doesn't hold true here.
They no longer have to be bigger, faster, more intelligent and stronger to survive as they would faced with natural competition and predation.
IF captive breeding is ever achieved on a large scale, selective breeding for reduced adult sizes would actually be of immense benefit both to the animals kept as "pets" and to the enjoyment of the owners as well.
The financial end of the hobby itself demonstrates over and over that what's best for the animals is actually of lesser importance than what sells products, and it's just basic common sense that almost no-one has the ability to provide the room and freedom even vaguely comparable to wild living sea creatures.
Sites and forums such as this one do all that is humanly possible to educate and include much more humaneness than is currently found in the hobby, and I'm among the most vocal in preaching that as close to natural is best in housing, food, selection, etc, etc, but is there room for compromise?
My Fuzzy Dwarf lions are thriving and spawning in a 125 gal. tank, rather than in a 20 or 29 gal. tank that I have available, although some (including me! ) would argue that my choice of tankmates is less than perfect, but to expect everyone to house these fish in tanks this big isn't realistic.
My position is that it's better to try and assist some folks who have fish in improper situations to maximize both the health and happiness of their animals and themselves than to alienate them entirely.
By doing so, it's my hope that some, if not many, will realize the benefits of larger tanks and do it because they begin to feel for their pets and WANT to.
For the people who still keep goldfish and bettas in glass jars, there's not much hope.

[John Roehrig]

It was the Scott Michael (and others) printed information that got me thinking about the topic in the first place. Let me be direct. I do not consider a 100 gallon tank small by any means. It is not, however, the "ocean" - nor is a 200 gallon tank. Many of the online fish dealers do not consider a 100 gallon tank too small for even many of the large angels.

Of course when I purchased these fish years ago I did not believe that they would live 10 years! Through the years, these fish continued to grow, and stabilized at their current size. They always thrived, seemed content, and were disease-free. I understand that 10 years for a PBT is pretty good! These fish did not appear dysmorphic. I have seen large, dysmorphic fresh-water fish, that have been returned to my LFS. These fish - usually cichlids - have always been associated with VERY small tanks.

When I finally had the time (and all of my house remodeling chores were completed), I upgraded and consolidated into the 100 gallon tank by returning the predatory CT to my LFS. The 100 gallon tank was as large as I could deal with from the perspective of space, cleaning, and water changes. I would contend that a well-maintained 100 gallon tank is a far better marine environment than a poorly maintained 200 gallon tank!

Many scientific "conclusions" are based on one or a few studies that are extrapolated out to many other situations. Even for the Juvenile hormone growth-inhibition argument, since fish are not inbred populations, for how many fish species has this mechanism actually been documented?

Through this thread I was just trying to get a handle on growth versus space.

Thanks again!

[ecugman]

Originally posted by .........M.Dandaneau

My position is that it's better to try and assist some folks who have fish in improper situations to maximize both the health and happiness of their animals and themselves than to alienate them entirely.

Can I copy and paste that statement into every Tang thread I see from this point foward????

I've grown very tired of the bickering and argueing in almost every thread here on RC involving stocking. Both sides of these arguments need to read that statement over and over and over and.................

Very well stated Mr./Mrs. Dandaneau!