THis is a VERY shty choice to be faced with....RTC,Tig, Planiceps, Wyckii, TSN, Niger.....hmm...If I had to pick one....he he he...Brachyplatystoma Flavicans
WOW, this is really tough... With unlimited space I'd scuba with a RTC whilst hand feeding.... But with only an 800 gallon on hand (not a big fan of ponds) I'd go with this guy:
Had one years ago and I believe it to have been liarius longibarbus or something of the sort. LOL
Tough choice and it's hurting my brain.. STOP IT!!