Can fish die because of aggression?

Question

One of my mollies died today :(

It had its gills swollen and body thinned out. But I dont think it was any disease. What I think it was that due to aggression from other molly and platy, it wasnt eating much and became thin.

But anyways its dead today. What could it be? Can fish die due to aggression?

Answer 1

No, your fish did not die of aggression.  Aggression is characterized by nipped fins and one fish chasing another fish.  Or one fish will just outright eat another.  If your dead fish did not have ripped fins, then the other fish were not biting at it and it did not die of aggression.  

Were the other fish chasing the fish that is now dead?  

If not, then your fish died for some other reason.  If they were, then maybe that stressed your fish and lead to its death.   But aggression deaths are easy to spot because the dead fish is all beaten up and partially eaten, and the other fish had been chasing the dead one for a while.

The gills swollen may be a sign of poor water quality.  Test your water for pH, ammonia, nitrite, and nitrate.

Answer 2

yes they can.But it might of died and then it could of gotten nibbled at him after he died.the other fish could of been aggressive and may have started to get mad at the molly because of territory reasons.Or the molly could be weak and when the fish is week the other stronger fish were being aggressive because the weak fish could not run or protect him self.

                                   hope this helps,

                                       -Jacob

Answer 3

it could easily die of stress if the other fish are agressive towards it

Answer 4

As a result of aggression toward them, yes.  Due to aggression from them to another fish, probably not, but anything's possible.