University of Alaska Anchorage

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Jill Prewitt

Jill Graduated Fall2007 with a MS in Biological Sciences

Thesis:

DEVELOPMENTAL AND ENVIRONMENTAL EFFECTS ON THE METABOLIC CHARACTERISTICS OF HARBOR SEAL (PHOCA VITULINA) MUSCLE

The metabolic characteristics of skeletal muscle vary with age, diet and condition, which can impact and be impacted by, activity patterns.  In wild animals this phenotypic plasticity can affect performance, foraging ability, and ultimately survival. Understanding the impacts of age, diet, and condition on muscle is particularly critical in marine mammals because their muscles must support activity in the absence of freely available oxygen. Thus, variation in factors that reduce oxygen stores or alter the ability of muscle to support aerobic, lipid based metabolism will negatively impact diving and foraging behaviors.

This study investigated the plasticity of muscle oxygen stores, metabolic enzymes, and the morphology of juvenile and adult harbor seals (Phoca vitulina).  The results indicated that pup muscles are immature at birth, with potential negative impacts on diving ability and survival.  Once mature, however, adult muscle was robust to the normal seasonal fluctuations in body condition, diet, and activity.

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