Physiological Consequences of Seasonality in Temperate Fishes: The Effect of Thermal Preferences on Energy Storage Strategies

Aquatic ectotherms are faced with seasonal fluctuations in metabolic rates and prey density that can drive distinct patterns in energy storage. Lipids are crucial for overwinter survival and successful reproduction in many aquatic organisms. My thesis investigated the effect of seasonality on lipid dynamics in fish with different thermal preferences. I conducted a comprehensive literature review of seasonal lipid levels in freshwater fishes. Then, I compared lipid and protein dynamics in a warm and cold water fish species sampled from Lake of Two Rivers in Algonquin Park. Seasonal lipid variation appeared widespread across thermal guilds, suggesting that energy acquired during warm months is universally important for overwinter survival and reproduction. Across-species, larger bodied fish had dampened seasonal lipid variation. Algonquin lake trout (cold water) exhibited more variable seasonal energy levels than smallmouth bass (warm water). These findings provide a new perspective on general physiological responses to seasonality in freshwater fish.M.Sc.2020-07-26 00:00:0