Over the course of their lives, salmon are known first as alevins and then fry, parr, smolts, grilse, and finally kelt.
'Smolt', 'grilse': as Richard Shelton observes, salmon are spoken of in a 'stained-glass language' of their own, their life stages marked by an ichthyological lexicon unchanged since Chaucer's time. Born in a 'redd', a shallow, gravel-covered depression dug by the female in the days before spawning, newly hatched salmon begin life as 'alevins', tiny, buoyant creatures with their yolk sacs still attached.