Total invested in white wine and fish (7)
I believe the answer is:
haddock
'fish' is the definition.
(haddock is a kind of fish)
'total invested in white wine' is the wordplay.
'total' becomes 'add' ('add' can be a synonym of 'total').
'invested in' means one lot of letters goes inside another.
'white wine' becomes 'hock' (hock is a kind of white wine).
'add' placed inside 'hock' is 'HADDOCK'.
'and' acts as a link.
(Other definitions for haddock that I've seen before include "Fish, often smoked" , "Fish like cod but smaller" , "Swimmer" , "Edible fish like small cod" , "N. Atlantic food fish" .)