title: Phenotypic plasticity in the common snapping turtle (Chelydra serpentina): long-term physiological effects of chronic hypoxia during embryonic development.
abstract: Studies of embryonic and hatchling reptiles have revealed marked plasticity in morphology, metabolism, and cardiovascular function following chronic hypoxic incubation. However, the long-term effects of chronic hypoxia have not yet been investigated in these animals. The aim of this study was to determine growth and postprandial O2 consumption (V̇o2), heart rate (fH), and mean arterial pressure (Pm, in kPa) of common snapping turtles (Chelydra serpentina) that were incubated as embryos in chronic hypoxia (10% O2, H10) or normoxia (21% O2, N21). We hypothesized that hypoxic development would modify posthatching body mass, metabolic rate, and cardiovascular physiology in juvenile snapping turtles. Yearling H10 turtles were significantly smaller than yearling N21 turtles, both of which were raised posthatching in normoxic, common garden conditions. Measurement of postprandial cardiovascular parameters and O2 consumption were conducted in size-matched three-year-old H10 and N21 turtles. Both before and 12 h after feeding, H10 turtles had a significantly lower fH compared with N21 turtles. In addition, V̇o2 was significantly elevated in H10 animals compared with N21 animals 12 h after feeding, and peak postprandial V̇o2 occurred earlier in H10 animals. Pm of three-year-old turtles was not affected by feeding or hypoxic embryonic incubation. Our findings demonstrate that physiological impacts of developmental hypoxia on embryonic reptiles continue into juvenile life.
authors.affiliation: Department of Biology, McMaster University, Hamilton, Ontario, Canada;
authors.forename: Oliver H
authors.initials: OH
authors.lastname: Wearing
authors.affiliation: Department of Biological Sciences, California State University San Marcos, San Marcos, California;
authors.forename: John
authors.initials: J
authors.lastname: Eme
authors.affiliation: Department of Biology, University of North Dakota, Grand Forks, North Dakota; and.
authors.forename: Turk
authors.initials: T
authors.lastname: Rhen
authors.affiliation: Department of Biological Sciences, University of North Texas, Denton, Texas dane.crossley@unt.edu.
authors.forename: Dane A
authors.initials: DA
authors.lastname: Crossley
mesh_terms: D000222:Adaptation, Physiological; D000367:Age Factors; D000818:Animals; D062186:Arterial Pressure; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism; D001835:Body Weight; D002319:Cardiovascular System / Q000196:embryology / Q000254:growth & development / Q000378:metabolism / Q000503:physiopathology*; D004435:Eating; D004625:Embryo, Nonmammalian / Q000503:physiopathology; D004734:Energy Metabolism; D006339:Heart Rate; D000860:Hypoxia / Q000097:blood / Q000196:embryology / Q000503:physiopathology*; D019344:Lactic Acid / Q000097:blood; D010101:Oxygen Consumption; D010641:Phenotype; D013997:Time Factors; D014426:Turtles / Q000097:blood / Q000196:embryology / Q000254:growth & development
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D019344:Lactic Acid
keywords: cardiovascular; hypoxia; oxygen consumption; phenotypic plasticity; reptile