Juvenile predator gets choice fish circling river (8)
I believe the answer is:
pickerel
'juvenile predator' is the definition.
(historical term for a young pike)
'choice fish circling river' is the wordplay.
I cannot quite understand how this works, but
'choice' could be 'pick' (synonyms) and 'pick' is found in the answer.
'river' could be 'r' and 'r' is present in the answer.
'fish' could be 'eel' (eel is a kind of fish) and 'eel' is found in the remaining letters.
This accounts for all the letters.
This may be the basis of clue (or it may be nonsense).
'gets' is the link.
(Other definitions for pickerel that I've seen before include "freshwater fish" , "Young or small pike; prick eel (anag.)" , "American fish" .)