Can anyone tell me what it means when Oscars shake their tail.

I assume you are talking about when they quiver their tails? I believe this is how the fish communicate with each other, I've seen on many occasions. I've heard people say that it is aggression but I don't believe this strictly true as I've never actually had any Oscars that have been aggressive with each other and they have done this on numerous occasions

Thank you, I think your right they do seem to be communnicating. I have two for almost two years and I just noticed them doing it and they're very friendly.

This is normal and is a very common occurance, they will even do it to non oscars

My O even quivers his tail sometimes, when my Bull Terrier comes close to the tank!lol

Noddy wrote:


Obviously your oscar doesnt like your bull terrier

delboybully wrote:


You got that right.
On the other hand, the strangest things can make my Oscar go crazy.
He once went nuts because there were 2 cardboard boxes on the side of the tank!
He kept going at them, puffing up and acting bad@$$
It seems like my Oscar counts the roomspace around the tank to his territory.
Or at least he acts that way.
That time i removed the boxes and he settled down.
He does not react that way to my kids.
I love those over-acted tantrums in my o.

Noddy wrote:


same when my staffordshire bull terrier goes too close to the tank, altho when the springer goes close to the tank the oscar scares it off! - same wi ma gf's little bro lol

my oscar reacted to a red ball put outside the tank...but
when my grand daughter put it inside the tank, they don't
mind at all. i believe fishes reacted on something they
could not reach out but don't mind at all once it is in their face.

I don't always count it as aggression....seems to me it's a statement of territory...but doesn't always mean it's going to lead to fighting. Kinda like you and I getting some 'elbow' room.