Model observed fish using ears (5)
I believe the answer is:
ideal
'model' is the definition.
(ideal can mean model or perfect)
'observed fish using ears' is the wordplay.
I cannot really understand how this works, but
'fish' could be 'ide' (type of fish) and 'ide' is present in the answer.
The remaining letters 'al' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for ideal that I've seen before include "unlikely to be bettered?" , "fine" , "Paradigm" , "superb specimen" , "The best conceivable" .)