Bully Giant Gold Danio

[shimek182]

My Gold Danio has suddenly become a bully. He constantly chases the other fish in my tank, even after he has gorged himself on most of the food I put in.
What would cause this sudden change in attitude?
I thought they were suppose to be a peaceful breed of fish
(He's over 2 inches and is about 1.5 years old).
He's IS the largest fish in my tank, but I as shocked at how mean he has gotten.
Any possible explanations???

 

[SubRosa]

Chasing is normal behaviour for Danios. As long as he's not doing damage when he catches them it's not a problem. Generally speaking most problems with schooling fish behaviour can be solved by increasing the number of individuals in it.

 

[jpappy789]

As Sub mentioned, it could be because of not having enough of it's own to pick at...how many other giant danios are in the tank?

 

[shimek182]

As Sub mentioned, it could be because of not having enough of it's own to pick at...how many other giant danios are in the tank?

He is the only danio I have.
He has been alone for as long as I have had him though, which is about 1.5 years.
Have never had any problems before.

 

[mesto]

I would get more danios for him, that way he can work out a pecking order within his school, the way his brain is telling him he has to do now.

 

[shimek182]

I would get more danios for him, that way he can work out a pecking order within his school, the way his brain is telling him he has to do now.

Well, I'm kinna maxed out on space (8 gallon, 7 fish).
I suppose I could get one more danio and see if that helps.

 

[jpappy789]

This danio is in an 8 gallon tank? That alone could be the problem...danios need WAY more space, even smaller species.

Cramped fish will act out.

 

[tanker]

Well, I'm kinna maxed out on space (8 gallon, 7 fish).
I suppose I could get one more danio and see if that helps.

8 gals and 7 fish?? That is the problem.

1) Danios are racers, they do need long tanks.
2) They are schoolers, you will need at least 6+. 10 is even better.
3) You cannot add anymore fish to that 8gal.

Sorry

 

[shimek182]

When I first got the danio, he was among the first group of fish I got,, I was a beginner.
Now I know a lot more about schooling fish and fish # per size of tank.
I thought the general rule was one fish per gallon?

 

[Fish-Addict]

When I first got the danio, he was among the first group of fish I got,, I was a beginner.
Now I know a lot more about schooling fish and fish # per size of tank.
I thought the general rule was one fish per gallon?

General rule, yes, but that doesn't take into account the behaviour of the fish. Danios need a lot of room to swim, so filling a 5 gallon tank with five 1-inch-long danios is NOT good, but putting the same five fish in a 40 gallon aquarium with 35 inches of other suitable fish IS acceptable, although in both examples you have not exceeded the "one inch of fish per gallon" rule.


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