Proximate Composition and Energy Density of Stream‐Maturing Adult Steelhead during Upstream Migration, Sexual Maturity, and Kelt Emigration

摘要: AbstractIn anadromous salmonids, muscle tissue provides the primary source of energy to support spawning migrations and spawning. We examined changes in lipid content, protein density white collected from stream-maturing Snake River–Columbia River steelhead Oncorhynchus mykiss during several phases reproduction. At a basinwide scale, we estimated that between early freshwater entry postspawning (kelt) emigration, content was reduced by 94% levels less than 1% wet weight. Lipid depleted more rapidly reproductive cycle afterward provided only remaining somatic for migration. found consistently higher sexually mature male females, suggesting allocation prior reproduction varies sexes. In kelts, were significantly higher...