Maximum fish sizes

[freshienow]

WOOT!!!! This is some great stuff!

 

[Dovii dude]

Getting back to the fish vs tank size topic,i believe the people who are asking if you are planning on getting a bigger tank soon or even a pond are only saying these things because they are trying to help,and to prevent the fishkeeper from failure ie...loss of fish,loss of money etc.I have learned more in 1 year from these people than i did in over 30 years of keeping fish.I know they mean no harm.

 

[Kobeclone]

I see both sides of the argument.

Some of the maximum sizes listed are obtainable. Perhaps even surpassed but that would lead me to believe the information wasn't recorded or researched correctly. That's probably neither here nor there though.

But there is a part where people get too overbearing with it. And every big fish someone gets they have to post "do you have a pond?" or list world record sizes as max sizes. Or in rare cases even dream up sizes worthy of being on "Monster Quest".

It annoys me only because I think it's annoying to ask every person with a fish that. Honestly you can't do much about it though. You will always have those people. And you'll never change their opinion. Does it sometimes seem like they want to drive people away from a species?? Yeah for whatever reason sometimes. But again you'll never change their attitude on keeping these large species.

 

[Moontanman]

The simple fact that almost no one on these kind of sites ever raise their predators to anything approaching full (i.e. average) size is a sign that proper conditions are not being provided. For instance, look in any fish market or fishing lodge in Central America, and you'll see just how large dovii can grow. Similarly, you can reel in P-Bass one after another when fishing in the Amazon basis that dwarf anything you seem to see in almost any private aquarium. Stunted grow is very definitely an unhealthy side effect of a less than ideal habitat. Any curator at a zoo or public aquarium will confirm that fact.

On the flip side, some fish actually grow larger in the aquarium than they do in the wild. Availability of food of a more nutritious profile and lack the of predation are usually the reasons. Members of the Mbuna group who normally feed on algae/aufwuchs grow much larger in aquaria after being fed nutrient dense foods.

It is not a complicated matter to provide what is necessary for full growth. Fish farmers do it all the time. The problem lies in being realistic with yourself when you acquire a fish. There are hundreds (thousands) of people on these sites that acquire fish that will never be truly provided what they need.

Not true dude, many of my ideas about fish size comes from people who are in charge of fish at zoos and public aquariums. They say fish can indeed be dwarfed and not hurt the life span or life quality of the fish. Many things we have no control over can decide the final size of a fish. One more thing when I say dwarfing a fish I am not talking about fish that stay in the few inch range and can be raised to beyond their usual wild caught sizes. If you feel the need to dwarf a fish that only gets to be 8" long then you are in the wrong hobby, small fast growing fish are far too easy to grow out in a perfectly reasonable sized aquarium. Some can even be pumped to be bigger than what they should be. I used to know a guy who bred small tetras and danio type fish and he would grow them out in conditions far better than any they might experience in the wild. His zebra danios were at least twice as big as any raised more naturally. he increased the oxygen content of the water, had a flow through from pristine well water , raised temps and lots of food, far more food than a fish would normally need or have access to. his fish were beautiful but they died quickly when removed from these more than perfect conditions, disease and shorter life spans decimated any that were sold. he sold a lot of them because they were so nice and big but their life spans were at best weeks in a normal aquarium. we can use food, temps, oxygen content to pump up a fish and have it live a short but spectacular life and we can keep a fish under really great conditions and have it live a long life but never get to even close to it's maximum size. On the other hand i feed my fish small amounts of very high quality food as close to what they would naturally eat as possible. If i feed the nutrition rich food i feed them small amounts of it. My cardinal tetras routinely live five years plus, in the wild they are almost never more than a year old, living hard and dieing young. All exothermic animals live and grow to the limits of the food and living space. we do them no favors by overfeeding them and trying to make them grow to unnatural sizes in the space they have. Even day length can affect the eventual size of a fish. I say feed a reasonable amounts (large amounts of food will cause growth but shorten the fishes life) keep the temps at a reasonable temps, keep the water clean and well oxygenated and let nature take it's course. In an aquarium a fish needs less food not more than in the wild, no need to stuff it full everyday. A fish will eat until the food comes out the rear undigested. As long as your fish is healthy and active you are doing a good job. An active predatory fish in the wild might not eat but every few days, Stuffing a such a fish full everyday shortens it's life, causes internal problems like liver disease and otherwise stresses the fish. Does this sound like a fish that is being treated the way it should be? I'm not saying starve them or keep them cramped up in too small containers, just treat them in a manner where their needs are met as they grow. Many of them will never reach their maximum sizes but they will live longer and be healthier.

 

[geeimatree]

you can never be too careful
what if you do get that fish that will grow that maximum size or even larger?
you gotta be prepared

 

[Arachnar]

Very interesting thread, read the whole thing, I don't have enough experience to comment on the subject but...

There's also the fact that some fish just die before they get very big and people assume that they were old or whatever. Or it seems to me that food and the fishes age have alot to do with it size, there are some fish like loaches that take forever to get to a large size.

I have a book currently checked out from the library that says Arapaima seldom exceed 2 feet in length in aquariums, now anyone on here has seen Johnptc's pimas and knows that a gross understatement. The fact may be that when the book was printed like 30 years ago, maybe the pimas never really got that big because they just died or got stunted or sold. The book also pretty much mention the fishes size in the aquarium and then says" rarely reaches wild size in the aquarium" and it goes half the size or knocks a couple inches off.

 

[Arachnar]

Not true dude, many of my ideas about fish size comes from people who are in charge of fish at zoos and public aquariums. They say fish can indeed be dwarfed and not hurt the life span or life quality of the fish. Many things we have no control over can decide the final size of a fish. One more thing when I say dwarfing a fish I am not talking about fish that stay in the few inch range and can be raised to beyond their usual wild caught sizes. If you feel the need to dwarf a fish that only gets to be 8" long then you are in the wrong hobby, small fast growing fish are far too easy to grow out in a perfectly reasonable sized aquarium. Some can even be pumped to be bigger than what they should be. I used to know a guy who bred small tetras and danio type fish and he would grow them out in conditions far better than any they might experience in the wild. His zebra danios were at least twice as big as any raised more naturally. he increased the oxygen content of the water, had a flow through from pristine well water , raised temps and lots of food, far more food than a fish would normally need or have access to. his fish were beautiful but they died quickly when removed from these more than perfect conditions, disease and shorter life spans decimated any that were sold. he sold a lot of them because they were so nice and big but their life spans were at best weeks in a normal aquarium. we can use food, temps, oxygen content to pump up a fish and have it live a short but spectacular life and we can keep a fish under really great conditions and have it live a long life but never get to even close to it's maximum size. On the other hand i feed my fish small amounts of very high quality food as close to what they would naturally eat as possible. If i feed the nutrition rich food i feed them small amounts of it. My cardinal tetras routinely live five years plus, in the wild they are almost never more than a year old, living hard and dieing young. All exothermic animals live and grow to the limits of the food and living space. we do them no favors by overfeeding them and trying to make them grow to unnatural sizes in the space they have. Even day length can affect the eventual size of a fish. I say feed a reasonable amounts (large amounts of food will cause growth but shorten the fishes life) keep the temps at a reasonable temps, keep the water clean and well oxygenated and let nature take it's course. In an aquarium a fish needs less food not more than in the wild, no need to stuff it full everyday. A fish will eat until the food comes out the rear undigested. As long as your fish is healthy and active you are doing a good job. An active predatory fish in the wild might not eat but every few days, Stuffing a such a fish full everyday shortens it's life, causes internal problems like liver disease and otherwise stresses the fish. Does this sound like a fish that is being treated the way it should be? I'm not saying starve them or keep them cramped up in too small containers, just treat them in a manner where their needs are met as they grow. Many of them will never reach their maximum sizes but they will live longer and be healthier.[/quote]
Wow a lot of writing but an interesting perspective. What's the lifespan anyway for some fish, in a river or lake with hundreds or even thousands of a species we may be more accurate in an average size estimate or by gaging how old these fish are. We use otoliths in salmon but what about those tiny tetras? If a fish lives in a lake the traces deposits in an hypothetical otolith might not be relavant to growth and seasonal water changes.

 

[cchhcc]

Not true dude, many of my ideas about fish size comes from people who are in charge of fish at zoos and public aquariums. They say fish can indeed be dwarfed and not hurt the life span or life quality of the fish. Many things we have no control over can decide the final size of a fish. One more thing when I say dwarfing a fish I am not talking about fish that stay in the few inch range and can be raised to beyond their usual wild caught sizes. If you feel the need to dwarf a fish that only gets to be 8" long then you are in the wrong hobby, small fast growing fish are far too easy to grow out in a perfectly reasonable sized aquarium. Some can even be pumped to be bigger than what they should be. I used to know a guy who bred small tetras and danio type fish and he would grow them out in conditions far better than any they might experience in the wild. His zebra danios were at least twice as big as any raised more naturally. he increased the oxygen content of the water, had a flow through from pristine well water , raised temps and lots of food, far more food than a fish would normally need or have access to. his fish were beautiful but they died quickly when removed from these more than perfect conditions, disease and shorter life spans decimated any that were sold. he sold a lot of them because they were so nice and big but their life spans were at best weeks in a normal aquarium. we can use food, temps, oxygen content to pump up a fish and have it live a short but spectacular life and we can keep a fish under really great conditions and have it live a long life but never get to even close to it's maximum size. On the other hand i feed my fish small amounts of very high quality food as close to what they would naturally eat as possible. If i feed the nutrition rich food i feed them small amounts of it. My cardinal tetras routinely live five years plus, in the wild they are almost never more than a year old, living hard and dieing young. All exothermic animals live and grow to the limits of the food and living space. we do them no favors by overfeeding them and trying to make them grow to unnatural sizes in the space they have. Even day length can affect the eventual size of a fish. I say feed a reasonable amounts (large amounts of food will cause growth but shorten the fishes life) keep the temps at a reasonable temps, keep the water clean and well oxygenated and let nature take it's course. In an aquarium a fish needs less food not more than in the wild, no need to stuff it full everyday. A fish will eat until the food comes out the rear undigested. As long as your fish is healthy and active you are doing a good job. An active predatory fish in the wild might not eat but every few days, Stuffing a such a fish full everyday shortens it's life, causes internal problems like liver disease and otherwise stresses the fish. Does this sound like a fish that is being treated the way it should be? I'm not saying starve them or keep them cramped up in too small containers, just treat them in a manner where their needs are met as they grow. Many of them will never reach their maximum sizes but they will live longer and be healthier.

You lost me at "dude."

 

[Zoodiver]

First off comparing growing fish to any growing mammal is funny, and pointless.

As for the comments about zoos/aquariums saying drawfing happens and it doesn't effect the life - care to state who that was and where they work?
Also, I'm sure it's being taken out of context. There are times when slaves in America were treated well - but that doesn't make the over all concept correct by anymeans.

In the real world of fish keeping, chances are that if you are keeping a fish in too small of a tank, your are hurting it long term. There are PLENTY of studies that show this. Sure you will always have an example of it working the other way - but nature is amazing in pulling that off from time to time. But we can't keep fish hoping for the oddities of life to pull us as keepers out of a jam.

 

[Moontanman]

First off comparing growing fish to any growing mammal is funny, and pointless.

As for the comments about zoos/aquariums saying drawfing happens and it doesn't effect the life - care to state who that was and where they work?
Also, I'm sure it's being taken out of context. There are times when slaves in America were treated well - but that doesn't make the over all concept correct by anymeans.

In the real world of fish keeping, chances are that if you are keeping a fish in too small of a tank, your are hurting it long term. There are PLENTY of studies that show this. Sure you will always have an example of it working the other way - but nature is amazing in pulling that off from time to time. But we can't keep fish hoping for the oddities of life to pull us as keepers out of a jam.

No you misunderstand what I am saying completely. I don't think that keeping a fish in a too small box to see if you can make it small is a good idea. I just think that trying to see how big you can grow a fish is counter productive to the fish. Most fish do not ever get to the maximum size in the wild, just because your fish does in captivity doesn't mean it is being kept to it's best interests. I bought a fish that had already been dwarfed, I didn't dwarf it but it was a healthy beautiful specimen even though it had been dwarfed. Keep your fish in good conditions, feed them the right amounts, don't try to stuff them to see how big you can make them be and if they don't make it to the maximum size it's not a indication you have done something wrong. in a confined space, and any aquarium is indeed a confined space no matter how big it is, even a pond is a confined space for some fish, a fish (AND I DON'T MEAN SMALL FISH) will not usually reach it's maximum size due to natural responses to being confined. Feeding a fish a huge diet full of unnatural amounts of nutrients is not good for the fish no matter how big it gets! Just like keeping a fish in water that is far to warm will speed up it's metabolism and make it age fast and die young. If you are buying a fish that gets far too big to fit in the tank you have then you need to realistically plan for a bigger tank but if the fish doesn't get to be 15 feet long that doesn't mean its been mistreated! I wouldn't be upset if a fish didn't reach any more than half to two thirds it's average size in the wild. This depends a lot on the fish, some are more flexible as to size than others but that is a good rule of thumb.