I think my fish is depressed....

so last summer, I got a 10 gallon fish tank/bowl, and some tiger barb and cherry barb fish.....not sure how many i've had. I killed a couple in the beginning. But I'd say I averaged about 10 or so. cute little suckers. then, in August, I got five piranhas. yes, I know. I said Piranhas. the face you have now is usually the look on the face of the folks in the pet store when they expect me to say I have some cutesy fish...ANYWAYS. When I got them, there were five, about the size of a quarter each. They were the same size as the tiger barbs.

They all coexisted fine. At first. But as the piranhas got bigger, things changed. If I forgot to feed em, or came home late, usually, a tiger was "missing". Miami carnival, being gone almost a week, was the end of any other fish in the tank.

They've since moved to a larger home/tank, and you'd think they would be a little more tolerant. NOT. Yes, I know they are aggressive fish, but dag! There were two bottom feeders, until Trinidad Carnival. Came back to just one.

They leave the one guy alone and I'm not sure why. Somehow, they've bonded with him. But no matter when I add a second, they eat him. If I feed them, then put him in. Put him in WHILE they are eating. After they eat. So I gave up. I just tried again. And my bottom feeder actually seemed happy! I think it was a girl to my assumed guy. They were all cuddled up (if fish can cuddle) getting to know each other. By the morning though, she was gone. And now my lonely guy is in the back of the tank, alive, but not moving. I think he's depressed.....