anchovy

It is yellow, in cage and it sings. What is it?
Anchovy.
But Karagoz, an anchovy does not live in a cage.
It does if I want to put it into a cage.
But an anchovy is not yellow either.
I have painted it.
Ok, then tell me, does an anchovy sing?
That's the witty part of the enigma.

in Selected Stories of Hacivat and Karagöz.