juvie growth

[brady]

Is there any scientific proof that large fish,5 1/2 in. produce a chemical that inhibits small fish 21/2 in. from growing? I have put 6 3mt olds with 45-6 mt old fish and I know years ago I heard it and I was wondering is that idea still floating around.
Jay

[brady]

Not 45 .Should read four 51/2 in fish.
Jay

[John_Nicholson]

No there is none that I am aware of. Jack Wattley made some comments about it years ago, but later decided that there was not anything to it. I do not think there has ever been any real scientific studies on it though.

-john

[Skip]

No scientific proof

[ShinShin]

John,

Jack was still talking about it in 2005. He brought it up in his talk at the ACA in Fort Worth. Has he flip-flopped since then?

Mat

[Discus Origins]

I don't think Jack ever changed his stance on the hormone theory, there was just never a scientific study done to prove or disprove it. He mentioned it to me on multiple occasions when we were shooting the sh*t in his garage in Ft Lauderdale back in early 90s.

[brady]

I was thinking after I posted asking the question, could it simply be a matter of the larger ones out competing the smaller ones at feeding time and also stressing them out with some pecking order thing going on?
Jay

[Skip]

I was thinking after I posted asking the question, could it simply be a matter of the larger ones out competing the smaller ones at feeding time and also stressing them out with some pecking order thing going on?
Jay

i think so.. since the larger ones are larger for a reason.. moving them around by size allows the others to grow also.. i did that in the past and saw my small pick up on growth.. once i grouped by size..

[John_Nicholson]

John,

Jack was still talking about it in 2005. He brought it up in his talk at the ACA in Fort Worth. Has he flip-flopped since then?

Mat

He and I were talking at one of the Dallas shows over dinner. I don't remember the year but not only did he say that he was misunderstood about it but it kind of made him mad. He said that he never claimed that there was a hormone the slowed down growth. He said that something in the water was slowing it down, but that could be anything including poor water conditions. Personally I think he has just changed his mind over the years.

-john

[PAR23]

I was thinking after I posted asking the question, could it simply be a matter of the larger ones out competing the smaller ones at feeding time and also stressing them out with some pecking order thing going on?
Jay

I also suspect this is the main reason......I think that because the frequency and amount of water changed by most hobbiest would not allow any hormones produced to reach significant levels. This view is based on logic, I have no data to support it.