What could cause a change in behavior?

I have 2 angelfish 2 neon tetra and 2 red coral plattys. I have had all of them for over a month and they all have gotten along fine. I had a third angel fish but she accidentally got killed 2 days ago when some decoration (which has since been removed to avoid further accidents) fell on top of her. Since the death of my angel my Platinium angel fish has gone from being quite peaceful to an overly aggressive attacker. I am a little worried about my other fish. I am wondering if the death of the one angel could have caused this change in behavior and how can i get her to be peaceful again.What could cause a change in behavior?
you had 3 angels are you sure of the sex of the Angel fish are you sure the one that was killed was not part of a pairWhat could cause a change in behavior?
The citizens of your tank are represented by two separate Yet equal important groups

The Police who investigate the crime

and the District Attorneys who Prosecute the offender



Here are there Stories *Doink Doink*



Det Logan:

What do we have?



Officer on the Sceen:

Detective, looks like a Gang hit and we have 2 whiteness



Logan walks up to the couple,



Det Logan:

Dont I know you?



whitenes1:

No man I aint Never Seen you before..



Det Logan:

Ok what did you see?



whitenes1:

Well this car..

then taked off down the ally



Runs in to Det Brisco

Det Brisco to Det Logan:

Mike you loose something?



Ok son lets see some ID.



whitenes1:

No I aint givin you Shi.



Det Logan as he frisks him pull out a 38, bag of white pouder and and ID..



Det Brisco:

When Well what do we have here?



Det Logan

Looks like a Saturday night special..



whitenes1:

Yo man It aint Mine. That was Planted I didnt do nothin...

I wana.Lawyer



Det Logan as he snifs the 38 looks up ans says:

It was fired not long ago, and that was the smartest thing you said all night Mr AngelFish..



*DOINK DOINK*

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