I agree with Beezer, but would elaborate a little bit. While retaining part of his egg sac, a fry is referred to as an alevin. Up until smolting, salmonids are usually referred to as parr in reference to the dark "fingerprint" marks along their sides (parr marks), these occur in all species except the humpy. Smoltification is the process through which a salmon, steelhead or cutthroat becomes able to survive in saltwater. The production of a substance called guanine which helps enable the fish to handle changed saline levels also causes color changes, his parr marks and the protective coloration that served him in a freshwater environment disappear. The fish takes on the bright, silvery coloration that he will wear until he ripens to spawn. The term smolt is applied exclusively to the downstream migrant, still in the river, who has taken on this silvery coloration. Once in the salt chuck he becomes a juvenile or sub-adult and finally an adult.
Among steelhead, repeat spawners are relatively rare, usually hens, and their percentage numbers can vary considerably from river to river (the numbers I have at hand indicate 4 to 14 percent in Washington, depending on the river), so there's no single easy answer to your question.
[This message has been edited by Preston Singletary (edited 01-22-2001).]
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