he was just giving you a kiss =) i dont think the chinese perch is that bright. anything that moves it will think its food. mine took a bite on a endi twice its size while it was swimming
thats good and bad.
bad part- they will eat themselves to death, literally.
good part- start subsituting the gold fish with cut shrimp, frzen minnows, anything other than goldfish. mine would only eat sinking pellets after a while, not even guppies.