Deep-sea anglerfish and literary introductions

This morning I found myself telling my students that the introductions to the translated novels we are reading are like male deep-sea anglerfish, which latch on to the larger female and become fused with her flesh, as in the pictures above. The introductions, at the same time as being small literary works in their own right, become an inseparable part of our reading of the whole. You say these things if you're let loose in a classroom at 8 in the morning, especially if almost no-one has managed to watch the film you're supposed to be discussing.

The picture above is taken from this page, which looks strange enough for a second look. I don't know the original source, though.