Chronicles of expectoration
The little archerfish, which spits jets of water, can be taught to recognize a specific human face and spit at it, according to a scientific report (wonky link, here). It helps when the face is presented in black-and-white, apparently.
Little humans can also be taught to do this. Indeed, modern politics were built upon the discovery that with enough repetition, a person can be taught to spit at anything.
“Boo, boo, bad man!” … I am quoting my late mother at a time when I was three years of age. For some reason I recall it. I do not remember, however, to whose face she was responding. Perhaps it was the one that belonged to Adlai Stevenson. I do remember that she preferred Eisenhower (though as a non-American was ineligible to vote).
Ambon damselfish can be even more personal. They can recognize each other’s faces. They may all look the same to us, but we have not their facility with light in the ultraviolet range. Seen in that, each damselfish has facial spots. It is dead easy to tell one from another. Were gentle reader an ambon damselfish, and another one was giving him grief, he could simply avoid the idiot’s company. As you would be only four inches long, and living in a coral reef, there would be plenty of places to dart in and hide. (Bad luck if the niche were occupied, already, by something that eats ambon damselfish.) I don’t think damselfish can spit, at least not as dramatically as archerfish, but I’m sure they have other ways to express their disapproval. Or trapped, perhaps, they smile and say they’re on their way to a meeting. (Can damselfish smile? Must check this.)
There is no aquarium, up here in the High Doganate at the moment, but I did keep goldfish as a child; and tried putting minnows in with them once. (Foolish experiment. Tadpoles did not thrive, either.) Alas, I had not the wit to check if my goldfish preferred Kennedy or Nixon. (Surely they would have supported Goldwater.)
See the picture and spit. Look at another and convey indifference. But what if the poor fish is presented with only two pictures, and wants to spit at both?