Nurse fish with twisted tail (5)
I believe the answer is:
angel
This clue could be a double definition.
'nurse' is the first definition.
(angel can informally mean a nurse)
'fish with twisted tail' is the second definition.
'angel' can be an answer for 'fish' (thesaurus). I am unsure of the 'with twisted tail' bit.
Can you help me to learn more?
(Other definitions for angel that I've seen before include "Theatre backer" , "Divine messenger" , "Spiritual being - financial backer" , "Heavenly being - 21 (anag)" , "One backing plays" .)