A fish, the jollytail (Galaxias maculatus).
Any small fish.
A small freshwater fish of the carp family, Phoxinus phoxinus and related species.
A relatively small and insignificant person or thing of relatively little consequence, importance, or value. Synonyms: small fry, small potatoes, nobody, no one
To fish for minnows.
To fish (especially for trout) using a minnow as bait.