title: Respiratory Function in Voluntary Participating Patagonia Sea Lions (Otaria flavescens) in Sternal Recumbency.
abstract: We measured esophageal pressures (n= 4), respiratory flow rates (n= 5), and expired O2and CO2(n= 4) in five adult Patagonia sea lions (Otaria flavescens, body mass range 94.3-286.0 kg) during voluntary breaths while laying down out of water. The data were used to estimate the dynamic specific lung compliance (sCL), the O2consumption rate ([Formula: see text]O2) and CO2production rates ([Formula: see text]CO2) during rest. Our results indicate that the resting tidal volume in Patagonia sea lions is approximately 47-73% of the estimated total lung capacity. The esophageal pressures indicated that expiration is passive during voluntary breaths. The average sCL of sea lions was 0.41 ± 0.11 cmH2O-1, which is similar to those measured in anesthetized sea lions and awake cetaceans, and significantly higher as compared to humans (0.08 cmH2O-1). The average estimated [Formula: see text]O2and [Formula: see text]CO2using breath-by-breath respirometry were 1.023 ± 0.327 L O2min-1(range: 0.695-1.514 L O2min-1) and 0.777 ± 0.318 L CO2min-1, (range: 0.510-1.235 L CO2min-1), respectively, which is similar to previously published metabolic measurements from California and Steller sea lions using conventional flow-through respirometry. Our data provide end-tidal gas composition and offer novel data for respiratory physiology in pinnipeds, which may be important for clinical medicine and conservation efforts.
authors.affiliation: Fundación Oceanografic de la Comunidad ValencianaValencia, Spain; Department of Life Sciences, Texas A&M University-Corpus ChristiCorpus Christi, TX, USA.
authors.forename: Andreas
authors.initials: A
authors.lastname: Fahlman
authors.affiliation: Dolphin Adventure Nuevo Vallarta, Mexico.
authors.forename: Johnny
authors.initials: J
authors.lastname: Madigan
keywords: breath duration; diving physiology; lung compliance; respiratory flow rate; tidal volume