Do Full Grown Discus Exude Growth Inhibiting Hormones That Stunt Growing Fish?

[DISCUS STU]

Years ago this used to be mentioned in the literature. Is it true or possibly misinformation? Any experience here or a current link to a study?

[John_Nicholson]

There are several threads here about it. They always end up in arguments. I don't think there is anything to it myself.

-john

[discuspaul]

There are several threads here about it. They always end up in arguments. I don't think there is anything to it myself.

-john

I feel the same way.

[Kal-El]

From my own experience I've grown out Juvie with adults in the same tank. They just weren't as big as I would like compare to ones in their own tanks without adults. I think their growth had more to do with the adults hitting the food first and being aggressive at the smaller fish during feeding. Thus, the Juvie had less food to eat and grow. I have much better results growing Juvie in their own tank until they were 4.5-5" before mixing with adults.

[John_Nicholson]

From my own experience I've grown out Juvie with adults in the same tank. They just weren't as big as I would like compare to ones in their own tanks without adults. I think their growth had more to do with the adults hitting the food first and being aggressive at the smaller fish during feeding. Thus, the Juvie had less food to eat and grow. I have much better results growing Juvie in their own tank until they were 4.5-5" before mixing with adults.

I would think your observations are correct.

-john

[pcsb23]

I'm fairly sure they don't. I used to run a systemised setup, basically a number of tanks all with the same sump filtration. I kept my adults and grow outs on this system, albeit usually in separate tanks. However the key thing is that each tank shared the water, they were all connected, think of it as one big fish tank with rooms ;). If there were hormones produced then all fish on the system would be affected, my juvvies grew out fine.

[YSS]

From my own experience I've grown out Juvie with adults in the same tank. They just weren't as big as I would like compare to ones in their own tanks without adults. I think their growth had more to do with the adults hitting the food first and being aggressive at the smaller fish during feeding. Thus, the Juvie had less food to eat and grow. I have much better results growing Juvie in their own tank until they were 4.5-5" before mixing with adults.

Years ago, I put three 2.5" to 3" juvies in my display tank with close to 20 adult discus. One died, one didn't get over 4", but the third one grew to over 6.5". Go figure.