Growth Inhibitor

[MGKelly]

Growth inhibitor

Is there any truth to young discus excreting a growth inhibitor?
This guy at my LFS said that’s one of the reasons you have to do water changes so often.
I’ve never heard this before, but could it be true?

Thnx, Joe

[Eddie]

Growth inhibitor

Is there any truth to young discus excreting a growth inhibitor?
This guy at my LFS said that’s one of the reasons you have to do water changes so often.
I’ve never heard this before, but could it be true?

Thnx, Joe

This subject has been brought up several times. Is it true, I highly doubt it. Some experts may say that its true. IMO, water changes have nothing to do with any growth inhibitor but I will say that not changing water can inhibit growth. :D

HTH

Eddie

[MGKelly]

thnx Eddie,

I don't think there is any truth to this, but was curious as it makes sense to why discus fry would benefit so greatly from WC, especially large % WC.

Joe

[DiscusKeeper403]

From what I have heard it has to do more with the DOCs in the water?

[Eddie]

From what I have heard it has to do more with the DOCs in the water?

;)

[MGKelly]

From what I have heard it has to do more with the DOCs in the water?


thnx DiscusKeeper,

I agree, but so far it doesn't seem that anyone knows for sure.

Joe

[mmorris]

If I remember correctly the argument against the presence of a growth inhibitor was that it would be rendered ineffective in the great expances of the river system. That theory is based on the notion that that is the primary purpose of the secretion, rather than a `side-effect', so to speak. That said, I have no idea. :)

[Tropheus]

This cannot be true and goes completely against the logic of Darwin and basic evolution. This means that fish have evolved a survival of the fittest tool within the confines of an aquarium over the past 50 years. In a river basin a "Magical Inhibitor" would be dilluted and have a aboslutley no effect on a near by fish. I can't believe anyone has bought into this theory.

It is much more logical to believe that the big fish is outcompeting the small fish for nutrition to grow and cause a stressful environment stunting growth. Oh yeah, and man caused Gloal Warming is BS.

[MGKelly]

Tropheus,

I had a conversion with the LFS owner that mentioned the growth inhibitor in discus. I also think it's baloney, but so far no one can refute the statement with scientific fact.

i think we can use darwin to both support or reject this. Discus spawn in the wild when the water levels are low, so it would probably make sense to secrete a GI until levels rise again and food and real estate become more plentiful.

OR maybe we can make some big money and design a filter to remove the secreted "Growth Inhibitor" :guitarist:

but honestly, I'm very interested in whether this is true or not.

Joe

[mmorris]

This cannot be true and goes completely against the logic of Darwin and basic evolution. This means that fish have evolved a survival of the fittest tool within the confines of an aquarium over the past 50 years. In a river basin a "Magical Inhibitor" would be dilluted and have a aboslutley no effect on a near by fish. I can't believe anyone has bought into this theory.

It is much more logical to believe that the big fish is outcompeting the small fish for nutrition to grow and cause a stressful environment stunting growth.

Again, you are assuming that growth inhibition is the primary purpose of the secretion, and so it's existance does not make sense. You might be right. But if there is such a thing, it may be that the secretion has a different purpose entirely, and growth inhibition is a side-effect we can only see in our tanks. Or not. :)

[David Rose]

I wish I secreted a growth inhibitor; especially, during holiday feasting! :D

Honestly, I grew up with being told that there was such a thing, but have never seen any scientific proof either way.

[Don Trinko]

All IMO; I have yet to see any data to back this theory up but I have seen lots of data that indicates that clean water is NECCISARY for discus to grow and be healthy. Don T.

[Tropheus]

I just feel like it has happened so many times in captivity, that some discus keeper said "I got it, some kind of toxin to keep rivals small". I am more of a person to say prove it. Like ghosts, people swear they are real, well no one can prove it or has hard evidence, just a bunch of camp fire stories or ghost hunters on TLC telling me about the room getting cold and "DID YOU HEAR THAT?"

I mean, if there was a growth inhibitor than there would be evidence in the water. It is complete speculation to assume that it exists than not. This isn't even up for debate in my opinion.

[namasgt]

I remember I read somewhere that the fish will grow to the size of the environment their in, due to releasing some kind of growth inhibitor in the water. Could be true, I don't know. I doubt that some one can put 10 Juvie Discus in a 20 gallon and do water change once a week with good feeding will grow as much as the same 10 discus in a 20 gallon with 3 to 4 daily water changes.
I think some one did such a test and the discus that had the more water change ( more than one time a day) grew much bigger than the ones that had regular once a day water change.


before discus I had a 29 gallon full of fish, one of the pairs were young parrot fish. they did not grow much at all. I was feeding them good but not many water changes. In the mean time I went back to the pet store and the ones they had left, grew considerably compared to mine during the months. All my fish were healthy and I never had any of them sick. It was until I started doing more water changes that the parrots start growing after about 9 months after purchase. Dont know how much It takes for a juvie parrot to grow into adult, but they really start growing when the WC was increased.

[MGKelly]

Tropheus,

Not to get off the subject of fish secreting a growth Inhibitor, but did you see the ghosthunters were the creepy shadow set off a motion detector?
Probably rigged or was it? I think there are many things in the world that are beyond our understanding, but growth inhibitors in fish aren't one of them.

Joe




I just feel like it has happened so many times in captivity, that some discus keeper said "I got it, some kind of toxin to keep rivals small". I am more of a person to say prove it. Like ghosts, people swear they are real, well no one can prove it or has hard evidence, just a bunch of camp fire stories or ghost hunters on TLC telling me about the room getting cold and "DID YOU HEAR THAT?"

I mean, if there was a growth inhibitor than there would be evidence in the water. It is complete speculation to assume that it exists than not. This isn't even up for debate in my opinion.

[Jhhnn]

Discus spawn in the wild when the water levels are low

Incorrect, or at least I think so. Discus spawn during the wet season, when the water is high and food plentiful.

I think the idea of a growth inhibitor was transferred from horticulture, where the primary growing tip of a plant creates a growth inhibitor which slows down the other growing tips. Jack Wattley, iirc, also advanced this theory wrt to discus.

For my money, water pollutants slow down fish growth in general, with some individuals being more susceptible than others, even among siblings. In the wild, the actual volume of water/discus is enormous, almost infinite, ten to the umpteenth power, regardless of the season. As has been said, production of growth inhibitor would be a waste of effort from an evolutionary point of view. That might not be true wrt killifishes or others who live in seasonal pools and puddles. Inhibiting the growth of others could be a survival factor under such circumstances.

In aquaria, I suspect that the feeding regimen can either support or diminish differential growth rates. Feed little bits many times a day and the most competitive individuals get the lion's share every go round- they're never satiated, and food availability is localized in the tank. Growth differential is large. Feed larger amounts less frequently and everybody gets to eat- the most aggressive first, everybody else down the pecking order next, and food is available in a more widespread fashion throughout the tank.

If the amount of food given to growing fish disappears in a few minutes, it's not enough to prevent differential growth. If it takes 20 minutes or so, the big guys were full after 5, taking the edge off their aggression, and the smaller fish get their turn at it. If there's food laying around in the tank after 30 minutes and nobody's eating it, then the serving was too large... The feeding dynamic in the wild is obviously much different, where discus don't directly compete for food at all. It's not like a pack of wolves with a caribou carcass, at all...

At least that's been my limited experience.

[Tropheus]

Joe

So you are saying that you believe what you see on TV? :D

It's a scary world we live in where truth is the only endangered species.

[MGKelly]

Jhhnn, you're right, Discus do spawn during the wet season. I just looked it up and it says that the water levels are 24-30 feet higher than the peak of the dry season.

So it seems a naturally secreted growth inhibitor would be useless in this intance.

Joe



Incorrect, or at least I think so. Discus spawn during the wet season, when the water is high and food plentiful.

I think the idea of a growth inhibitor was transferred from horticulture, where the primary growing tip of a plant creates a growth inhibitor which slows down the other growing tips. Jack Wattley, iirc, also advanced this theory wrt to discus.

For my money, water pollutants slow down fish growth in general, with some individuals being more susceptible than others, even among siblings. In the wild, the actual volume of water/discus is enormous, almost infinite, ten to the umpteenth power, regardless of the season. As has been said, production of growth inhibitor would be a waste of effort from an evolutionary point of view. That might not be true wrt killifishes or others who live in seasonal pools and puddles. Inhibiting the growth of others could be a survival factor under such circumstances.

In aquaria, I suspect that the feeding regimen can either support or diminish differential growth rates. Feed little bits many times a day and the most competitive individuals get the lion's share every go round- they're never satiated, and food availability is localized in the tank. Growth differential is large. Feed larger amounts less frequently and everybody gets to eat- the most aggressive first, everybody else down the pecking order next, and food is available in a more widespread fashion throughout the tank.

If the amount of food given to growing fish disappears in a few minutes, it's not enough to prevent differential growth. If it takes 20 minutes or so, the big guys were full after 5, taking the edge off their aggression, and the smaller fish get their turn at it. If there's food laying around in the tank after 30 minutes and nobody's eating it, then the serving was too large... The feeding dynamic in the wild is obviously much different, where discus don't directly compete for food at all. It's not like a pack of wolves with a caribou carcass, at all...

At least that's been my limited experience.

[discussmith]

It's funny to me that one uses an unproven therory as fact to disprove another unproven therory.