Hormonal stunting?

[ChiefZero]

Ello all,

I was just thinking a while back my LFS said that if you have several discus the alpha pair will release hormones that will stop or slow done the other discus from growing. I think this sounds like rubbish but what do you all think/know?

Thanks
Bryant Stephens

[jesx57]

Yeah, I've heard it too when I've been researching. I do know that they release some slime coating into the tank.

But, if you do frequent water changes, keep your water parameters in check and feed a variety of good quality food, then there shouldn't be any problem.

[Doug Osborn]

You have to wonder how such a mechanism could evolve possibly evolve in river system fish. Given the 'water change' volume of a river flow, there seems no way to transmit or receive the hormones other than direct/immediate contact.

Cheers,
Doug

[ChiefZero]

Thats true but If you think about it near the edge of the water flows less as well if there are things that break the water like plants rocks etc. So it kinda makes sense to me.

[Tariq]

I have unheard of it and I think that it is true, but with heavy feeding and water changes they should be alright!

[Doug Osborn]

It's a curious thing, there are a number of online refs to it although nothing with much rigour behind it. Many reports suggest it's adult discus affecting juveniles.

http://www.zestweb.com/articles/growth/growth.html
http://lists.thekrib.com/gsas-member/0502/msg00032.html
http://www.petfrd.com/forum/articles.php?action=viewarticle&artid=88

I've seen aleopathy at work in plants (Eucalypts) but this still puzzles me.

Cheers,
Doug

[Tucson Reef]

Clown fish (Amphiprion and Premnas varieties)do it in the ocean, they even change sex. You take 6 or 8 juv. clowns in a large tank, one will dominate and grow largest, the Female. The next will grow slightly and become the male, the rest will stay neutral till one of the pair dies. The female can not go back to male but the male will become the female. The next dominate clown will take the males place. Now this happens in the ocean so It is a physical/visual cause again the hormones would be constantly diluted. Now I have a question, I have 2 juv Discus approx 6-7 centimeters or 2 1/2", one has pointed tip at rear of dorsal (male)l and the other has very rounded tip (female). But the one I think is female is the aggressor, am I wrong or is this possible while they are young? Its not a real bad war, just at feeding. I would prefer to stay with the two if I am right as they would make a beautiful pair.