growth inhibiting hormone

[dadecountyalan]

i was told by gabe posada a couple years ago that larger discus release a hormone that stunts smaller fish in the tank.

is this really true because ive been getting flamed everytime i say this.

[ericatdallas]

lol, I don't think anyone has offered any proof of this... this goes back to the Jack Wattley experiment I think. It's speculative and I don't see a lot of people talking about it any more. Most people now believe it's due to contaminants and dirty water.

It doesn't seem to be advantageous to stunt your offspring though. <shrug>

[Skip]

Find my thread "jack wattley method" it worked for me.. My slow growers really took off after I grouped by size...

[Keith Perkins]

Jack was right WAY more than he was wrong, wish I could say that. Don't know if the growth inhibitor hormone is true or not, but I wouldn't have flamed you for mentioning it. It might just be contaminants and dirty water that inhibit growth, but there's too much going on in water chemistry that's beyond me for me to just dismiss the possibility of fish producing a growth inhibitor.

[dadecountyalan]

im posting this because as some of you might have seen in another one of my threads i lost 2 of my adults due to a bad heater and im down to one lonely(but beautifull) adult in a bb 55g. and im planning on buying fish from dan(elite aquaria) but they are not going to be the same size. maybe an inch shorter. i dont want stunted fish.lol

[John_Nicholson]

Jack will tell you that he absolutely never said there was a growth inhibiting hormone. He said that there was something in the water that would stunt the growth. My guess would be nitrates.

-john

[dadecountyalan]

ive never met jack. but his "subordinate" gabe posada is the one that drilled this in my head. good news then. im going to go ahead and not worry about that hormone then:)

[Skip]

The bottom line was that jack had success grouping by size... Yes or no? For what ever thr reason is..

[Keith Perkins]

Here's exactly what Jack actually said. From his Handbook of Discus, page 34, paragraph 6. "It is a known fact that frog larvae release a substance into the water that inhibits normal growth of other tadpoles in the same water. If the tad poles are unduly crowded the largest one will greatly surpass the others in growth. This largest tadpole produces something that will serve to inhibit the growth of the smaller ones. Possibly this is the reason that one young discus can outgrow all the others in a tank, in many cases to double the size of those remaining. This huge discrepancy in size exists even when there is sufficient food for all, with the same amount of good being available to all the fish. This extreme difference in size has never existed in my hatchery because of the larger-than-average water changes".

[John_Nicholson]

You will notice that the word hormone is not mentioned. I have talk directly to Jack about this and any mention of him stating that a "growth surpressing hormone" exist will piss him off big time. I have also seen Jack while here for a talk kill 1/2 of the fish that Gabe sent as a club donation because the quality was so poor.

-john

[Skip]

back to jack.. whatever his reason.. he did keep them in same size groups growing out.. or is this a myth? i just want to know if that is true or not..

[Keith Perkins]

Agreed John, and he also says Possibly this is the reason that one young discus can outgrow all the others in a tank.

Oh sure Skip, make me read some more. :) I'm 99.9% sure you're right, but I'll look.

[dadecountyalan]

You will notice that the word hormone is not mentioned. I have talk directly to Jack about this and any mention of him stating that a "growth surpressing hormone" exist will piss him off big time. I have also seen Jack while here for a talk kill 1/2 of the fish that Gabe sent as a club donation because the quality was so poor.

-john


because his fish come from far far west!

[Keith Perkins]

Skip, this may not be exactly what you're looking for but its what I found quickly and does talk about him separating his fry. Page 107: "After about a week of this feeding (his secret egg formula), Wattley uses newly hatched brine shrimp naulpii to supplement the diet. Once the larger fry begin eating nauplii his task is lightened. He separates out the larger fry and feed them brine shrimp while the smaller fry stay on the egg diet until they are large enough to ingest the tiny newly hatched brine shrimp."

[Skip]

thanks.. :)

[John_Nicholson]

because his fish come from far far west!

LOL...Oh the "secrets" just keep coming out....

-john

[dadecountyalan]

i actually have a pretty good story of fish my friend bought from him but i dont want to post it here. i have a feeling i might get in trouble some how. lol

[moon_knight1971]

I gotta take a picture of this Red Spotted Green juvie I have. I got 5 of them at 3 months old (2 inches at the time) and this 1 juvie is twice as large as the other 4. It's literally like looking at a gorilla and then seeing Mighty Joe Young lol. Pics maybe when I get off work....

Joey!

[John_Nicholson]

Probably more to do with pecking order then anything else.

-john