Fish very quietly netted by chap (5)
I believe the answer is:
guppy
'fish' is the definition.
(guppy is a kind of fish)
'quietly netted by chap' is the wordplay.
'quietly' becomes 'pp' (musical abbreviation for pianissimo).
'netted by' is an insertion indicator (I've seen this in other clues).
'chap' becomes 'guy' ().
'pp' going within 'guy' is 'GUPPY'.
'very' acts as a link.
(Other definitions for guppy that I've seen before include "Aquarium fish" , "Freshwater fish" , "Small fish of northern South America and the Caribbean" , "Tropical fish" , "Tank occupant" .)