I'm fairly certain this is a result of nipping because I've watched this little guy getting bullied around the tank recently. Everyone was getting along just great. We went on vacation for a week and had a friend coming over to housesit. When we came back, one of my little cobra guppies was missing and I found what was left of him during a water change when I lifted one of the tank decorations. After that, my fiancé chose some new fish for his birthday including two new guppies for that tank. At first I noticed the new fish picking on the older ones but as time went on, only one was getting singled out and there was only one major and one minor bully still picking on him and they were two of his oldest tank mates! Now I know if one is sick, the others will pick on him...pretty much until he dies. At first I thought they had fin rot so I've been treating with salt; however, I'm fairly certain it's just tail nipping. I've quarantined the weakling but I need a new set of eyes on if his tail is getting better or worse. I'd love for it to grow and flourish like it once did. This is Dexter, named for his once beautifully blood-red tailfin. The pictures are in order 1. prior to nipping 2. first day of quarantine 3. second day of quarantine