Strange Discus Behavior?

[dapellegrini]

Not sure quite how to search for an answer on this, so thought I would make a quick post and see if anyone can comment...

I currently have 6 discus in a heavily planted 65-gallon. Bought them around 2-3 inches and they are now mostly 4-5 inches in size. Two Pigeon Bloods have paired off and are now on their 4 set of eggs in one corner. With this last egg cycle, another discus has become very aggressive toward the couple. After many fights, this other discus has now somehow earned a spot in their "breeding corner", and insists on being their to bully the two. Oddly when s/he is there, s/he turns almost entirely black. No signs of illness otherwise, eat, poops and acts normal. But seems to turn black as a kind of aggressive behavior toward the couple. As soon as I come near the tank s/he immediately shifts to normal colors (it is a Red Turq if that matters) and swims away. Then back to black when s/he returns to bug the others.

To be clear, s/he is not always black - but probably half the time I glance in the tank, but enough for it to seem odd to me. The others do not do this.

This RT (is that the proper abbreviation for a Red Turq?) used to be the smallest in the tank, and is now probably the largest. S/he used to be picked on by the others, now seems to rule over them.

I do not have much experience with discus - should I be worried or is this kind of thing normal, and perhaps a sign it is time to decrease the numbers in this tank?

[Eddie]

Probably trying to spawn with one of the paired fish.


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[Ryan]

Are you sure there isn't a threesome going on?

Normally, a discus that goes completely dark like that is either spawning or raising fry. They do flash their colors on and off to signal things like aggression, territorial disputes, breeding, etc. but usually the solid dark colors are a way to attract their fry.

Is the fish in question allowed to get near the eggs? If so, does it attempt to fan them and care for them? Do you see a breeding tube down on the dark-colored fish?

I ask this because it's not uncommon for young discus to all jump in on spawning action. In the last two batches of young discus I raised, I had 3 and 4 fish at a time making runs up a breeding cone, all trying to spawn and lay eggs together. I'm thinking the same thing Eddie mentioned -- the dark fish is just attempting to hijack the pair and spawn with one of the other fish.