i have just got an 6" udc (i thought it was a featherfin) but it swims upside down all the time so i guess its a udc not featherfin (they look the same eccept the swimming habbits i guess)
this one was eating lance fish (frozen) this morning
They're great, funny, entertaining fish. Supposedly they swim upside down to eat the bugs and eggs floating at the surface of the water. But they will turn over to get stuff at the bottom. Have fun w/ your new fish!