Fish from Brazil brought up — ace! (4)
I believe the answer is:
tuna
'fish' is the definition.
(tuna is a type of fish)
'brazil brought up ace' is the wordplay.
'brazil' becomes 'nut' (I've seen this in another clue).
'brought up' says the letters should be written in reverse (in a down clue, letters go up).
'ace' becomes 'a' (abbreviation).
'nut' backwards is 'tun'.
'tun'+'a'='TUNA'
'from' is the link.
(Other definitions for tuna that I've seen before include "Large fish for the strange aunt" , "Fish; edible cactus" , "Tinned food fish" , "Tunny" , "Yellow-finned fish" .)