Thank you, Sir Bygber. We agree.
I don't know how we got from Humphrey Bogart in THE MALTESE FALCON and KEY LARGO to CHINATOWN and fish, but there may be a connection, with Humphrey Bogart, at least. I would think that, in the 1930's, the time of CHINATOWN, Jake Gittes and Noah Cross would have been eating trout, which is generally served with the head on.
For those of us fascinated by the fact that Gittes looks into the trout's LEFT eye, you might want to glance at an extensive an extensive review I wrote of CHINATOWN. [I am indebted to an early colleague, who pointed out the many visual references to "left handed" things in the Picture.]:
Can anyone tie up any more "loose ends" here?
On that "sinister" note, I take my leave.