hmm. not too many cod here in aus get sold to eat. it would be very uncommon so see them in a fish monger. Most cod for eating get sold in high asain areas. but you choose them from a tank, still alive.
Hes a freshwater cod, but ive got some salt still in there from hes early days, because we had a bit of a whitespot outbreak.
i feed him cocktail prawn (sorry if that means nothing to you). just little saltwater prawn, pre-pealed and de-vained. he loves him, can eat 10 in a sitting.