Growth strategy of juvenile lake sturgeon (Acipenser fulvescens) in a northern river

Seasonal and size-related changes in proximate composition and energy of lake sturgeon were examined for a population from the northern portion of the species' geographic distribution. Condition factor increased with total length of lake sturgeon but did not differ among seasons. Whole body and muscle water, protein, lipid, inorganic, and energy contents increased with total length. Generally, values for each proximate component and energy content for sturgeon of a given size did not vary between June and October but were different in March. Lipid and protein contents varied inversely with water when each was expressed as a percentage of whole body weight. Hepatosomatic index declined with total length and did not differ between June and October; in March, values were lower. The relative water, protein, and inorganic content of liver decreased and lipid and energy content increased with total length. For lake sturgeon of a given length, the relative lipid content and energy content of liver were lowest in March and the lipid content was highest in July, the inverse of the finding for protein and water content.