For the past few months my cyano has been killing of his tank mates Blue Gouriams there were 6 of them to start with. About an hour ago I looked in the tank and they were all swimming good. I just looked in the tank and one of the gouriams is lying by the cyanos cave now there is 2 left. My question is the gouriam does not seam to have any damage to him his scales are ok so how does the cichlid do the damage.I can only assume that is was from aggression from the Texas. I never see an attack but the cyano does a little chasing to move the gouriasms around. I put the gouriam in isolation because he is still twitching not sure if will recover though. opinions?