bad historical meme: goldfish swallowing
It’s unclear exactly when the fad of swallowing live goldfish began, but by 1939 it was a national craze. University students competed to become the goldfish-swallowing champion by swallowing dozens of live fish at a time. Animal rights activists, lawmakers, and doctors objected to the fad, citing animal cruelty and risk of gut parasites. The craze ended relatively quickly, but never died out completely - I just Googled “goldfish swallowing” and the second result was for a really unsettling fetish website.
Who knows, maybe your great-grandparents were into vore?