The Zippy strip has advanced to #3 in the “Speechless” series (first two installments — or instalments, if you will — here and here), and moved from silence to vocalizations that are and are not “speech”:
There’s an overwhelmingly large literature on various kinds of symbolism and conventionalization in utterances. Ah-ooga, used to represent the sound of an automobile horn, most notably a Ford “Model A” horn (there’s even an ahooga website, for owners and restorers of Model A’s), falls in with a big class of cases, of several types — ouch and ah-choo and cock-a-doodle-doo and whoosh among them — that are expressive or sound-symbolic but also conventionalized to the point where they can be pronounced like ordinary words (rather than sound effects), though they can also be set off to some extent from the material surrounding them by various levels of “performance”, rather than mere utterance.
Now, you ask, the fish, what about the fish? How do we get from ah-ooga to landing a fish, or the reverse? Here I’m not up enough on Zippyconography, though the fish looks vaguely familiar. Maybe some kind reader can help.