Band member displays fish (9)
I believe the answer is:
trumpeter
'fish' is the definition.
The definition and answer can be both animals as well as being singular nouns.
Perhaps there's an association between them I don't understand?
'band member' is the wordplay.
I cannot quite understand how this works, but
'member' could be 'peter' (peter is a kind of member) and 'peter' is found in the answer.
This may be the basis of the clue (or it may be nonsense).
'displays' acts as a link.
Can you help me to learn more?
(Other definitions for trumpeter that I've seen before include "Jumbo?" , "Brass player" , "Boastful" , "Instrumentalist - type of swan" , "sends out signals?" .)