Aggressive Discus

[Spoon]

Hello All,

I was hoping someone could explain some of the aggressive behaviors of my discus and any way to reduce them. I have a 45 gal. with one discus, one angel, several rasbora and several neons. I added a slightly smaller discus today. The older discus has spent some time chasing the new guy around.

Does anyone know what triggers this behavior? SOme people have suggested that stripes and/or coloration effect how other fish react, any comments?

Also, the older discus almost seems to know he is being "bad" When I come up to the tank he goes to a corner and hides. But he did this before the new guy came in.

[Allivymar]

My guess is its territorial behavior. Your older discus considers the space in the tank "his" and now you've put in a possible usurper.

You may want to try redecorating the tank and moving things around to change the boundary lines that your older discus has set. No guarantees, but worth a try.

Heh, and I'd hide too if something 100x my size started poking around my place. Although not if I were my black lace angel. Lil bugger tries to take EVERYTHING on, including the gravel vac...

[Voodoo Chilli]

Although discus are generally considered a peaceful species, they are cichlids. As such, they can be territorial and aggressive.

I'd suggest completely rearranging your tank so everyone starts out on a level playing field and doesn't feel the need to protect their territory from intruders.

[lmw80]

If both of the discus are male, they may tend to be even more territorial than if there is a female and a male....do you know what the sexes of the discus are?

[Spoon]

I have no idea what sex the fish are. I can look on line and see if there is an easy way to sex the fish. I may also try rearranging the tank.

Also, good point about being 100x my size.

[glstine]

What kind of discus is it? I've got two blue diamond and two brown scribble, the blud diamonds become quite bullyish at feeding time. Other than that they all get along together quite well. I had one of the blue diamonds and added the other three. The original blue was quit aggressive towards the others and I tried moving him to another tank for a couple of weeks(twice) and putting him back. Did no good. Now both of the blue diamonds are quite the bullies and the brown scribbles are about half the size of them, probably because they don't get as much to eat. I'm convinced the blue diamonds are somewhat of an aggressive species compared to other discus.

[Spoon]

I am not sure what kind he is, but here is a picture.

I don't have any pics of the new guy. The new one is about 20% smaller and he's mostly black with blue stripes.