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DEVELOPMENT ENHANCES HYPOMETABOLISM AND THE DIVE RESPONSE IN NORTHERN ELEPHANT SEAL PUPS
Author(s) -
Tift Michael Scott,
Houser Dorian,
Crocker Daniel
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.lb721
Subject(s) - foraging , pco2 , respiration , ontogeny , biology , venous blood , physiology , ecology , medicine , anatomy , anesthesia , endocrinology
We investigated the development of the dive response and diving capacity by measuring; 1) changes in O2 consumption (VO2) 2) changes in venous blood gases and hemoglobin saturation and 3) comparing rates of O2 use between terrestrial apneas and submergences. Hypometabolism during breath‐holds increased across development, reaching a maximum suppression of 53% from RMR late in development. There was a 17% suppression in VO2 during voluntary breath‐holds at the end of the developmental period. Hypometabolism increased with breath‐hold duration and was further reduced during submergences. Similar patterns of increased O2 conservation across development and during submergence were seen in the slower rates of pO2 depletion. This study demonstrates the physiological cue for stimulating respiration in northern elephant seal pups is the build‐up of pCO2 across a breath‐hold. Reduced O2 storage directly limits diving capabilities and likely influences foraging success in seals forced to depart to sea prior to achieving full developmental diving capacity. Our findings highlight the critical importance the duration of the developmental period in seals has on increasing breath‐hold capacity and underlies the significant role that facial immersion has in down‐regulating blood O2 use in diving seals.