Tank in question is a 29g community. I had a school of head and tail light tetras. I had been gone to my in-laws house only returning a while ago. But just a moment ago, I looked over in the tank to see one tetra hovering toward the back. As my eyes focused, I noticed the bottom half of his tail was gone. So, I leaned in close and noticed too, that someone had really nipped his tail end good. He was missing his "tail light" and the culprit had also not just gotten the tail fin, but a nicely hunk of his body at the back end as well. This fish was not schooling, not fearful of my approach and did not respond when the net came near him, so I went ahead and pulled him and euthanized him.
My question is, has anyone heard of aggression within a school of this specie? He was not the smallest fish and I have not seen any aggression in these fish since I have picked them up, granted, that was only Friday and now is Sunday night. Tankmates are as follows: 6 mollies (two trios), 4 coryadoras, the now 5 head and tail light tetras and 2 otocinculus cats. One of the mollies is pregnant (surprise surprise) and I have seen her being territorial, but usually only near the bottom of the tank and only toward the other Black mollies. She seems content to let the Cories and even the golden lyretail mollies pass through without harassment. Usually she is even ok with the male black molly until he starts getting... nosey in that livebearer "come to papa" sort of way.
Anyway, any input is appreciated.
My question is, has anyone heard of aggression within a school of this specie? He was not the smallest fish and I have not seen any aggression in these fish since I have picked them up, granted, that was only Friday and now is Sunday night. Tankmates are as follows: 6 mollies (two trios), 4 coryadoras, the now 5 head and tail light tetras and 2 otocinculus cats. One of the mollies is pregnant (surprise surprise) and I have seen her being territorial, but usually only near the bottom of the tank and only toward the other Black mollies. She seems content to let the Cories and even the golden lyretail mollies pass through without harassment. Usually she is even ok with the male black molly until he starts getting... nosey in that livebearer "come to papa" sort of way.
Anyway, any input is appreciated.
