“Fry” refers to a recently hatched fish – salmon or otherwise – that has reached the stage where its yolk-sac has almost disappeared and its swim bladder is operational to the point where the fish can actively forage and feed for itself, although fry are generally reliant on filter-feeding rather than tackling solid food.
Fry are generally regarded as fish at a stage between hatchlings, which are less mobile, and fingerlings, which have developed scales and fins and are able to consume small invertebrates.