Fish size

That is not common sense that is good ethical concern mixed in with appropriate fish husbandry.. I do not think anyone here is saying put a whale shark in a 20 gallon. What I am saying is there are conditional factors to take into account when housing any fish, you can not pigeon hole this into a blanket rule. What one may say is an improper tank size, someone else may be spawning their fish in. We really are not in disagreement here Arthur, I do know what you are saying, I do not disagree with you, but in saying it in a vague manner one can come up with 40 different exclusions that test it. Hence it becomes a dogmatic truism that is not exactly encompassing of all species needs or situations. Loads or Anecdotal and empirical information also clearly states that certain species do not reach sizes in captivity that they do in the wild. With a clear knowledge and understanding of the mechanics of fish growth and physiology (on a species basis) some of these hobby truisms really are kind of silly...(in some cases actually detrimental)
Again this is not true... Fish do not always live longer in captivity when compared to their wild average even when kept properly.. Some might, I'm not arguing this, but this is not a fact. Some species in captivity will burn out much faster than they do in the wild just because conditions are too good. Some good examples of this are with some Minnow species, Killifish and Livebearer species and of coarse my favorite the Lamprey .. Again you can not blanketly say all species will react to fit the same pigeon hole we give them...

Perhaps I have been a bit vague. I know that the topic itself is a sticky one. I feel however that what the OP is eluding to is a dangerous thought process. What he calls "dwarfing" a fish most would call "stunting" a fish and stunting a fish in all the examples I can think of is not a good thing. Not even in nature. Some species stunt easily and seem to survive without a problem. Trout are a good example. Stream trout don't reach the size that lake dwelling trout do but they also don't live nearly as long. Sunfish stunt easily as well but this is due to negative environmental factors (overpopulation, lack of resources, inbreeding etc.) and also is of no benefit to the fish. Stunting is known to have negative side effects on various species. Perhaps I'm just speaking for myself here but I always though that proper fishkeeping meant taking the best possible care of the fish that you can provide. If that is done there should be very little to hinder growth. Nitrates and ammonia, pH, diet, temperature, DO, stress...all these factors play a part in fish growth. To try and purposely dwarf a fish because it might be easy to do so would require caring for the fish improperly. I know you agree but I'm not sure the OP does.

I'm sorry but I cannot agree with you based on your one example of an iridescent shark not growing beyond 10". I can think of many cases where iridescent sharks outgrew their tanks, proof that they don't "dwarf easily". I think it is ignorant to assume that because it happened once it is safe to intentionally try to stunt others.

I am sorry I mislead you, this is not the first fish I have seen become stunted or even the first iridescent shark, this one just happened to be the last and my favorite, since he was eaten by an egret it was especially upsetting. Yes I know about iridescent sharks out growing their tanks, I also know of several that didn't. What is the difference we are missing, doesn't that at least arouse your curiosity? I've also seen it in native fish, at least other peoples native fish. The unknown is what drives my intellect, the urge to know should be at least part of drives us to keep fish, I know that was what caused me to start growing swamp trees in aquariums, scuba diving, bonsai, statistical analysis, breeding fish, astronomy, and all the other things I want to know the why about!


Michael Hissom
aurea mediocritas

If you guys were talking about putting a fish with a large growth potitial in a 5 gallon aquaium just because it was small at the time I would be total agreement with you but none of seem to have noticed I kept the fish right from the start in a 125, it lived it's summers ina 2000 gallon pond and summers here are sometime seven even eight months long. If that fish was ever going to get bigger than it did it would have. All through this thread many of you have assumed a tiny tank with a big fish even though I plainly told the tank size several times. I think some of you are just hoping I'll get out of hand or do something so you'll have a reason to complain. devoir avoir honte

Moontanman
aurea mediocritas

Edited by Moontanman, 09 March 2008 - 05:02 PM.

The drama is again starting to far outweighing the credible discussion, which had nothing to do with native fish, on growth in captivity versus nature.

I'll make three points.

Regardless of what size tank you give it, it's still captivity, it's not a natural environment. Growth and behavior is inherently altered from the time you bring a fish into captivity. Richard's examples about optimal conditions are a perfect example. Go take a look at the football shaped hooked jawed brook trout that are in 1000s of gallon tanks in various aquariums.

The last time I checked North Carolina is still well above tropics and summer does not last seven or eight months.

A few fish that don't follow the typical pattern of growth in captivity wouldn't arrose my curiousity much at all....statistically speaking they are outliers at best.

The drama is again starting to far outweighing the credible discussion, which had nothing to do with native fish, on growth in captivity versus nature.

I'll make three points.

Regardless of what size tank you give it, it's still captivity, it's not a natural environment. Growth and behavior is inherently altered from the time you bring a fish into captivity. Richard's examples about optimal conditions are a perfect example. Go take a look at the football shaped hooked jawed brook trout that are in 1000s of gallon tanks in various aquariums.

The last time I checked North Carolina is still well above tropics and summer does not last seven or eight months.

A few fish that don't follow the typical pattern of growth in captivity wouldn't arrose my curiousity much at all....statistically speaking they are outliers at best.

Too bad you've never lived in South Eastern NC, our proximinity to the gulf stream gives us weather much warmer than most of NC. or even SC or Georga for that matter. Plants and animals live here that cannot live either north or south of us. I've keep tropical fish out doors from the middle of april to the middle of october sometimes well into november, other than that you are exactly correct but my point was i didn't try to grow a fingerling large fish in a tiny aquarium to stunt it's growth as most people assumed.

Edited by Moontanman, 09 March 2008 - 07:34 PM.

The drama is again starting to far outweighing the credible discussion, which had nothing to do with native fish, on growth in captivity versus nature.

I'll make three points.

Regardless of what size tank you give it, it's still captivity, it's not a natural environment. Growth and behavior is inherently altered from the time you bring a fish into captivity. Richard's examples about optimal conditions are a perfect example. Go take a look at the football shaped hooked jawed brook trout that are in 1000s of gallon tanks in various aquariums.

The last time I checked North Carolina is still well above tropics and summer does not last seven or eight months.

A few fish that don't follow the typical pattern of growth in captivity wouldn't arrose my curiousity much at all....statistically speaking they are outliers at best.

Bye the way there was a highly succesful plecosotmus farm here in the early 70's abnd 80's. It produced millions of plecostomus during it's operation. Tropical no, sub tropical and unusually warm most of the time yes. Ground water here is well above the 70 degree mark year round.

The last time I checked North Carolina is still well above tropics and summer does not last seven or eight months.

He's got alligators and palm trees in his neck of the state. That corner of NC is pretty warm most of the year.

That said, I have serious doubts about the captive husbandry of these stunted fish. I suspect some combination of old filter media and insufficient/infrequent water changes to achieve this sort of stunting with the tankbuster species mentioned. Something in the fundamentals is amiss here.

He's got alligators and palm trees in his neck of the state. That corner of NC is pretty warm most of the year.

That said, I have serious doubts about the captive husbandry of these stunted fish. I suspect some combination of old filter media and insufficient/infrequent water changes to achieve this sort of stunting with the tankbuster species mentioned. Something in the fundamentals is amiss here.

I have a 16 inch Longnosed gar that is 9 years old that is in a 240 gallon with a 100 gallon sump Wet / dry filter system that receives a 50% to 75% waterchange weekly... Several other Longnosed have out grown the tank and have been moved.....Explain it...

Fish is fed a highly varied diet BTW....and also is on a seasonal temp and photo period standard.

Please tell me how this is related to stunting by poor husbandry standards or protocal...

I think one of the problem with this discussion is what the definition of stunted is. Seems to me there are a couple/few different types of smaller than normal size.
Trout were mentioned a few times. I picture the perfect, fully proportional, healthy tiny little brookies in the headwater streams. Then I picture the small, skinny, big head, ugly looking lakers over populating lakes without good forage.
The latter I consider "stunted" and is not a healthy, desirable condition. On the other hand, the little brookies are not dwarfs. They will grow big given the right conditions. It would seem the size of their environment is affecting their growth.
I think the same is true in captive environments. Poor husbandry can "stunt" fish while healthy, well kept fish may not grow as big in a small tank. Is it the same, or different?
FWIW, I agree with those that say it is ethical to strive to keep any captive animal in the most comfortable and healthy environment possible.
I also have an aesthetic issue with my tanks looking as natural as possible. A great big fish that can barely turn around in a tiny little tank just does not look pleasing to my eye.

WOW
I can stunt any fish if I choose not to do water changes. I can feed the heck out of them, and they still won't grow. Now look at that in a natural situation, and two main things come into play. Food availability, and individual variation.
I keep cattle, lots of them. We have from time to time what we call poor doers. They eat as much, have as much room, but never gain weight, or size. Their bodies are ineffiecient. They are not "strong" animals. I would say this may apply to Richards small gar.
Now look at Green sunfish in a tiny ditch. If there were only one, he would be large. But if there are two, they spawn. Now you have 300. Mom and dad only eat 250 of them. Now you have 52 fish in the same pool of the tiny ditch competing over the same amount of food. What would you expect the ultimate results to be? Smaller fish.
You cannot take a single example, and apply it widely. Your irredescent is a poor doer.

WOW
I can stunt any fish if I choose not to do water changes. I can feed the heck out of them, and they still won't grow. Now look at that in a natural situation, and two main things come into play. Food availability, and individual variation.
I keep cattle, lots of them. We have from time to time what we call poor doers. They eat as much, have as much room, but never gain weight, or size. Their bodies are ineffiecient. They are not "strong" animals. I would say this may apply to Richards small gar.
Now look at Green sunfish in a tiny ditch. If there were only one, he would be large. But if there are two, they spawn. Now you have 300. Mom and dad only eat 250 of them. Now you have 52 fish in the same pool of the tiny ditch competing over the same amount of food. What would you expect the ultimate results to be? Smaller fish.
You cannot take a single example, and apply it widely. Your irredescent is a poor doer.

Hey BTW that spotted gar of yours is a god damn pig man.... Sucker wolfs down both pellets and various other foods like there is no tomorrow... Just thought I'd mention that...Awesome fish and I'm very happy with it....I am very confident BTW to call this one as an Oculatus especially now that I have personally looked it over.

I guess this is off topic though.....

He's got alligators and palm trees in his neck of the state. That corner of NC is pretty warm most of the year.

That said, I have serious doubts about the captive husbandry of these stunted fish. I suspect some combination of old filter media and insufficient/infrequent water changes to achieve this sort of stunting with the tankbuster species mentioned. Something in the fundamentals is amiss here.

I use an over flow trickle filter with a 55 gallon sump on a 125 gallon aquarium, I grow Azolla Carolinas in the sump, it forms a layer about one inch thick and helps keeps my water parameters at a very high level. I also grow bald cypress, water tupelo, and swamp apples in my tank along with lots of native vals and cattails. I've grown hog chokers from fry so small they still had eyes on both sides of their heads to 10" long. they even went through what my wife called mating rituals which I still doubt since I didn't see them. They were eventually farmed out to a marine aquarist who promptly killed them. Nothing like watching a hog choker sit on a smooth rock like a hawk waiting to swoop down on his prey. Great fish if you can get them to grow. I can catch them by the dozens at times. inland silversides are my fav fish and if anyone knows about silversides they are very difficult to keep alive. They must have excellent water quality especially a high oxygen content. I even managed to ship a box of them via the US mail! I use rain water for water changes usually around 60 gallons or so a month. That is just in my 125, I have lots of ponds where I breed blue spotted sunfish, least killifish, blue fin killies, and gambusia by the thousands to feed my redfin pickerels I have yet to breed but I am trying. I am also partial to dwarf mudpuppies, dwarf sirens, and mud turtles. I keep clams and mussels in my tanks (I have to leave out the trickle filter to do that) and they even reproduce (the clams not the mussels) I am interested in all things aquatic and am always on the look out for new inverts to culture. Large limpets, tiny freshwater spider crabs"Amarinus lacustris", dwarf crayfish "Cambarellus shufeldtii" there is a whole world out there of small fish and inverts to keep. I do not dwell on dwarfing fish, I was just trying to report on it happening and that I didn't think it was such a bad thing if the fish are well taken care of. Now since I was forced out of my house I am starting all over, in a way it's a good thing if I can avoid all the mistakes of the past I should be able to get my aquaculture license renewed and keep on breeding and shipping live native fish.

Edited by Moontanman, 10 March 2008 - 12:38 AM.

I think one of the problem with this discussion is what the definition of stunted is. Seems to me there are a couple/few different types of smaller than normal size.
Trout were mentioned a few times. I picture the perfect, fully proportional, healthy tiny little brookies in the headwater streams. Then I picture the small, skinny, big head, ugly looking lakers over populating lakes without good forage.
The latter I consider "stunted" and is not a healthy, desirable condition. On the other hand, the little brookies are not dwarfs. They will grow big given the right conditions. It would seem the size of their environment is affecting their growth.
I think the same is true in captive environments. Poor husbandry can "stunt" fish while healthy, well kept fish may not grow as big in a small tank. Is it the same, or different?
FWIW, I agree with those that say it is ethical to strive to keep any captive animal in the most comfortable and healthy environment possible.
I also have an aesthetic issue with my tanks looking as natural as possible. A great big fish that can barely turn around in a tiny little tank just does not look pleasing to my eye.

We have not been talking about a deformed fish or fish so large they cannot turn around. A 10" fish in a 125 is usually considered a reasonable size. The fish wasn't deformed in anyway and had no defects you usually see on these fish such as eyes missing from hitting the glass at high speed or other wise damaging themselves. Personally I think at least part of it was the factor the tank only had a clear front, the rest of the tank was opaque and the fish saw it as a barrier to be avoided so he didn't hit it and damage himself.

I have a 16 inch Longnosed gar that is 9 years old that is in a 240 gallon with a 100 gallon sump Wet / dry filter system that receives a 50% to 75% waterchange weekly...

Please tell me how this is related to stunting by poor husbandry standards or protocal...

I think that you may have answered your own question. Have you considered that even though it may seem like you're doing frequent and heavy water changes, you may still not be changing enough water frequently enough for its needs?

I have a 16 inch Longnosed gar that is 9 years old that is in a 240 gallon with a 100 gallon sump Wet / dry filter system that receives a 50% to 75% waterchange weekly... Several other Longnosed have out grown the tank and have been moved.....Explain it...

So you're suggesting that because one out of several (you said it yourself) longnose gar didn't outgrow the tank that it is safe to assume others won't outgrow the tank either? I think your example proves that fish will outgrow a tank. The gar you have could have any of a number of things wrong with it that perhaps you just were not aware of. Maybe it was more stressed then the other fish. Perhaps it was genetically inferior. Whatever the case may be it doesn't sound like tank size is whats limiting the fish's growth.

We have not been talking about a deformed fish or fish so large they cannot turn around. A 10" fish in a 125 is usually considered a reasonable size. The fish wasn't deformed in anyway and had no defects you usually see on these fish such as eyes missing from hitting the glass at high speed or other wise damaging themselves. Personally I think at least part of it was the factor the tank only had a clear front, the rest of the tank was opaque and the fish saw it as a barrier to be avoided so he didn't hit it and damage himself.

Do you know for certain what a deformed iridescent shark looks like? How about internally? Even if the fish looks fine on the outside do you know what was going on inside? Be it one gar out of several or one iridescent shark out of several it still is not the norm for either species to remain small and is not any kind of proof that a fish will only reach the size the tank allows. These fish are oddities influenced not by tank size but by other factors within the system or by their genetics.

Edited by sandtiger, 10 March 2008 - 11:21 AM.

Do you know for certain what a deformed iridescent shark looks like?

Yes

How about internally?

No

Even if the fish looks fine on the outside do you know what was going on inside?

No

Be it one gar out of several or one iridescent shark out of several it still is not the norm for either species to remain small and is not any kind of proof that a fish will only reach the size the tank allows. These fish are oddities influenced not by tank size but by other factors within the system or by their genetics.

It was quite few iredecscent sharks not one, if you had read my posts you would have seen the tank I kept it is was more than big enough for it to have grown much larger. I've seen the same thing in other fish as well.

Your claim that fish only reach the size a tank allows is a pretty radical one. If you want anyone to take it seriously you need to be more specific. How many iridescent sharks have you kept? How many remained small? How many other fish have you had this happen to? You gave us an outline of your setups but neglect to mention anything in the way of temperature, water parameters, longevity etc. A lot of factors influence fish growth. If this is something you're researching I assume you have notes on these important details. I don't believe the tank is the factor. It is either the individual fish's genetics or husbandry related.

Your claim that fish only reach the size a tank allows is a pretty radical one. If you want anyone to take it seriously you need to be more specific. How many iridescent sharks have you kept? How many remained small? How many other fish have you had this happen to? You gave us an outline of your setups but neglect to mention anything in the way of temperature, water parameters, longevity etc. A lot of factors influence fish growth. If this is something you're researching I assume you have notes on these important details. I don't believe the tank is the factor. It is either the individual fish's genetics or husbandry related.

MY temps are always with in the 65 to 85 degree range depending on the time of year, I watch my fishes health to judge water parameters, test kits are a joke and are wildly inaccurate way to expensive for me to use on a regular basis. Since I generally keep my fish in very hard black water i don't us GAC. I did mention growing hog chokers from fry to 10" adults and I did mention keeping cardinal tetras for more than five years when they seldom live more than a year in the wild. I also keep inland silversides which will not live in water that isn't in very good condition. It's an effort just to get them back to the aquarium after collection. Don't ask me any more questions until you've read all my posts.

Michael Hissom
Captive Environments, aquaculture

Your claim that fish only reach the size a tank allows is a pretty radical one. If you want anyone to take it seriously you need to be more specific. How many iridescent sharks have you kept? How many remained small? How many other fish have you had this happen to? You gave us an outline of your setups but neglect to mention anything in the way of temperature, water parameters, longevity etc. A lot of factors influence fish growth. If this is something you're researching I assume you have notes on these important details. I don't believe the tank is the factor. It is either the individual fish's genetics or husbandry related.

It's not radical it used to be considered a fact 35 years ago or so, I've never claimed it works on all fish just some of them and I think it's important to know which ones they are, pacu obviously are not one of the ones that stop growing. I do have theory that so many iridescent sharks are being produced as food fish they have inadvertently created a smaller version of the fish they are culturing. On the other hand this occurs in so many fish I often wonder if some fish just naturally have individuals that never come close to their maximum size.

Michael Hissom
Captive Environments, aquaculture