Nurse got fresh fish (8)
I believe the answer is:
sturgeon
'fish' is the definition.
(type of fish)
'nurse got fresh' is the wordplay.
'fresh' is an anagram indicator (a fresh re-ordering of the letters).
'nurse'+'got'='nursegot'
'nursegot' is an anagram of 'STURGEON'.
(Other definitions for sturgeon that I've seen before include "caviar suppliers" , "Caviare-yielding fish" , "Fish - got nurse (anag)" , "Caviar supplier" , "Caviar-producing fish" .)