You've done some really fine work here, and that fish is simply gorgeous!
What I notice, in terms of crits and likeness, is that the bridge of his nose and his nasal bone look wider and flatter in the portrait. There is so much in shadow in the photograph. Here it is lightened, showing the angle and shape of the nasal bone as it tapers towards the bridge, with some space between his glasses and his nose.
Hope that is helpful in finalizing your wonderful portrait! It looks like a proud moment for a fisherman!