I once had a 55 gallon with a common pleco, four clown loaches, and five zebra danios. Last week I noticed that there was only one danio left, along with a danio carcass. Now there are no danios and no bodies. Input? Anyone? I figure they didn't beat each other up because the single danio has vanished now. The loaches are the likely culprits, but why? How? They can't be hungry, unless they don't eat what I give them, which is flakes and carnivore pellets.