title: Seasonal variation in blood and muscle oxygen stores attributed to diving behavior, environmental temperature and pregnancy in a marine predator, the California sea lion.
abstract: Survival depends on an animal's ability to find and acquire prey. In diving vertebrates, this ability is directly related to their physiological capability (e.g. oxygen stores). We studied the seasonal variation in oxygen stores, body temperature and body condition in California sea lions (Zalophus californianus) (CSL) as a function of seasonal variation in temperature, primary productivity, diving behavior and reproductive stage. During summer, blood oxygen stores were significantly greater and muscle oxygen stores were significantly lower than in winter. Total oxygen stores, body condition and body temperature did not change between seasons but variations in body temperature were greater during summer. Changes in oxygen stores are partly attributed to diving behavior, temperature and pregnancy that could increase oxygen consumption. Blood and muscle oxygen stores appear to be influenced by reproductive state. Blood oxygen stores are more likely influenced by diving behavior and temperature than muscle oxygen stores.
authors.affiliation: Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Center for Ocean Health, 100 Shaffer Rd., Santa Cruz, CA 95060, USA. stella.villegas@gmail.com
authors.forename: Stella
authors.initials: S
authors.lastname: Villegas-Amtmann
authors.forename: Shannon
authors.initials: S
authors.lastname: Atkinson
authors.forename: Alberto
authors.initials: A
authors.lastname: Paras-Garcia
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Costa
mesh_terms: D000818:Animals; D001831:Body Temperature; D002980:Climate; D004242:Diving / Q000502:physiology*; D004967:Estrogens / Q000097:blood; D005260:Female; D006454:Hemoglobins / Q000378:metabolism; D018482:Muscle, Skeletal / Q000378:metabolism*; D009211:Myoglobin / Q000378:metabolism; D010100:Oxygen / Q000097:blood* / Q000378:metabolism; D011235:Predatory Behavior; D011247:Pregnancy / Q000378:metabolism*; D011374:Progesterone / Q000097:blood; D046070:Sea Lions / Q000378:metabolism / Q000502:physiology*; D012621:Seasons; D012623:Seawater; D013696:Temperature
chemical_list: D004967:Estrogens; D006454:Hemoglobins; D009211:Myoglobin; D011374:Progesterone; D010100:Oxygen