Insect presented by a bird to a fish (9)
I believe the answer is:
cockroach
'insect' is the definition.
(cockroach is a kind of insect)
'presented by a bird to a fish' is the wordplay.
'presented by' is a charade indicator (letters next to each other).
'a bird' becomes 'cock' (cock is a kind of bird).
'to a fish' becomes 'roach' (roach is a kind of fish).
'cock'+'roach' is 'COCKROACH'.
(Other definitions for cockroach that I've seen before include "So-called black beetle" , "Household insect pest" , "Cork coach can be a pest" , "Rock coach turns out to be an insect" , "See pest" .)