Guppies

[farla]

Mom bought a bunch of guppies as part of stocking a new tank. We got six, so they wouldn't bully any one guppy too much, and two of each variety, so they'd have a friend. But it turns out the guppies formed into pairs and one of each variety bullied the other. (And in each case it was the smaller one. One of the pairs had a particular big gap, with the larger one twice the size and with a magnificent tail, and he was being chased about by the tiny shrimp with the pathetic tail.) We just got through rearranging the tanks to split them up.

I really wonder why. I'm thinking it might be that because they came from the same tank they already had an established pecking order, or else that perhaps guppies are more aggressive to similarly colored guppies.