Ive found a barramundi in with the goldfish I got,it was doing okay I guess,still alive too!
But yeah,I see lots of gambusia,crayfish,and sunfish(can't really identify) with the feeders.I remember accidentaly feeding a bass as a feeder to my aro,though it's not the first time I've seen a bass(mostly largemouths)with the feeders,or fed one to my fish(I've done it twice).I sometimes see kissing gouramis too,dunno what they're doing there.
Though I when I feed feeders I give them blue gouramis and SOMETIMES goldfish,though only as a treat.