For decades, anglers and diners along the New South Wales coast have encountered kingfish that dissolve into mush upon cooking — a quiet, recurring mystery with no clear culprit. Now, researchers have named what was always there: a microscopic parasite called Unicapsula seriolae, present in nearly two-fifths of wild kingfish tested, yet invisible to the eye, undetectable before cooking, and silent in the majority of the fish it inhabits. The discovery does not resolve the danger so much as reveal the depth of what remains unknown — about how the parasite behaves, why only some fish show sympto