title: Tracking the Development of Muscular Myoglobin Stores in Mysticete Calves.
abstract: For marine mammals, the ability to tolerate apnea and make extended dives is a defining adaptive trait, facilitating the exploitation of marine food resources. Elevated levels of myoglobin within the muscles are a consistent hallmark of this trait, allowing oxygen collected at the surface to be stored in the muscles and subsequently used to support extended dives. In mysticetes, the largest of marine predators, details on muscular myoglobin levels are limited. The developmental trajectory of muscular myoglobin stores has yet to be documented and any physiological links between early behavior and the development of muscular myoglobin stores remain unknown. In this study, we used muscle tissue samples from stranded mysticetes to investigate these issues. Samples from three different age cohorts and three species of mysticetes were included (total sample size = 18). Results indicate that in mysticete calves, muscle myoglobin stores comprise only a small percentage (17-23%) of conspecific adult myoglobin complements. Development of elevated myoglobin levels is protracted over the course of extended maturation in mysticetes. Additionally, comparisons of myoglobin levels between and within muscles, along with details of interspecific differences in rates of accumulation of myoglobin in very young mysticetes, suggest that levels of exercise may influence the rate of development of myoglobin stores in young mysticetes. This new information infers a close interplay between the physiology, ontogeny and early life history of young mysticetes and provides new insight into the pressures that may shape adaptive strategies in migratory mysticetes. Furthermore, the study highlights the vulnerability of specific age cohorts to impending changes in the availability of foraging habitat and marine resources.
authors.affiliation: California State University Channel Islands, Camarillo, California, United States of America.|The Keiki Kohola Project, Lahaina, Hawaii, United States of America.
authors.forename: Rachel
authors.initials: R
authors.lastname: Cartwright
authors.affiliation: California State University Channel Islands, Camarillo, California, United States of America.
authors.forename: Cori
authors.initials: C
authors.lastname: Newton
authors.affiliation: Hawaii Pacific University Stranding Program, College of Natural and Computational Sciences, Hawaii Pacific University, Kaneohe, Hawaii, United States of America.
authors.forename: Kristi M
authors.initials: KM
authors.lastname: West
authors.affiliation: Oregon Marine Mammal Stranding Network, Marine Mammal Institute, Oregon State University, Newport, Oregon, United States of America.
authors.forename: Jim
authors.initials: J
authors.lastname: Rice
authors.affiliation: International Fund for Animal Welfare, Yarmouth Port, Massachusetts, United States of America.
authors.forename: Misty
authors.initials: M
authors.lastname: Niemeyer
authors.affiliation: Alaska Veterinary Pathology Services, Eagle River, Alaska, United States of America.
authors.forename: Kathryn
authors.initials: K
authors.lastname: Burek
authors.affiliation: California State University Channel Islands, Camarillo, California, United States of America.
authors.forename: Andrew
authors.initials: A
authors.lastname: Wilson
authors.affiliation: California State University Channel Islands, Camarillo, California, United States of America.
authors.forename: Alison N
authors.initials: AN
authors.lastname: Wall
authors.affiliation: California State University Channel Islands, Camarillo, California, United States of America.
authors.forename: Jean
authors.initials: J
authors.lastname: Remonida-Bennett
authors.affiliation: California State University Channel Islands, Camarillo, California, United States of America.
authors.forename: Areli
authors.initials: A
authors.lastname: Tejeda
authors.affiliation: California State University Channel Islands, Camarillo, California, United States of America.
authors.forename: Sarah
authors.initials: S
authors.lastname: Messi
authors.affiliation: California State University Channel Islands, Camarillo, California, United States of America.
authors.forename: Lila
authors.initials: L
authors.lastname: Marcial-Hernandez
mesh_terms: D000818:Animals; D004242:Diving / Q000502:physiology; D018507:Gene Expression Regulation, Developmental; D024510:Muscle Development; D018482:Muscle, Skeletal / Q000254:growth & development* / Q000378:metabolism; D009211:Myoglobin / Q000378:metabolism*; D014907:Whales / Q000254:growth & development* / Q000378:metabolism
chemical_list: D009211:Myoglobin