On
3/11, I acquired 2 large(~3") Pajama Cardinals. They were an impulse buy, they were trade ins and I could the price was too good to pass up.
I put them in a 20H by themselves. From here on I am going to call the slightly larger fish
PJ1 and the smaller of the two,
PJ2.
They definitely did not like each other. After two nights of beatings,
PJ2 had tattered fins, and a large red fleshy wound on it's jaw.
___________________________________________________________
So assuming that I had gotten unlucky and had two fish of the same sex, on
3/13, I added 3 more large (again ~3") Cardinals to the tank.
I'm going to call these fish
PJ3,
PJ4, and
PJ5. Again going from largest to smallest, though in reality, all of these fish are about the same size. Though
PJ2 and
PJ5 are clearly a bit smaller than the others and
PJ2. So in order of size (largest first) it goes like this.
PJ3,
PJ1,
PJ4,
PJ2,
PJ5.
Interestingly,
PJ1 continued to spend most of time harassing
PJ2. And when
PJ1.
gets tired of chasing
PJ2,
PJ3 takes over the job of harassing
PJ2.
PJ5 is also the target of aggression from
PJ1 and
PJ3, though to a much lesser extent than
PJ2.
PJ4, seems to be neutral. Nobody harasses him, and he does not harass anybody.
PJ1,
PJ3, and
PJ4 got along fairly well, they occasionally will make faces at each other (Pushing their chin down to make their face look taller, very much like dottybacks do when they are mad) but physical contact was very rare.
_______________________________________________________
On
4/5, the aggression toward
PJ2 finally pushed him over the deep end. It is now missing half of it's lower jaw.
I removed
PJ2 to a tank by himself. I'm doubtful that it will survive. It still eats, though with much less gusto than before. And even if it does survive, it is still worthless from a breeding perspective, as it could never compete for food with only half of a mouth.
____________________________________________________
After removing
PJ2, the dynamics changed.
Now,
PJ3 does most of the chasing. And he is chasing of
PJ5.
PJ1 also joins in on chasing
PJ5 as well, but it is no longer the most aggressive fish.
And then
PJ4 who was more or less left alone before, is now getting beat up by both
PJ1 and
PJ3. But the attacks on
PJ4 are very different from the attacks to
PJ5 PJ2. When they attack
PJ4 they are very quick strikes at his side or tail. While aggression toward color=green]PJ5[/color] and
PJ2 are much slower targeted at it's belly.
_____________________________________
All of this has left me a bit undecided how to proceed.
I suspect that
PJ1 ,
PJ5, and
PJ5 are one sex, and
PJ2 and
PJ5 are the other.
So right now I am at a 3:1 sex ratio, which is probably not ideal.
I am tempted to pick up a few more and hope to even out the ratio. But I am also concerned about overcrowding as this is only a
20 gallon aquarium.