title: Swimming for your life: locomotor effort and oxygen consumption during the green turtle (Chelonia mydas) hatchling frenzy.
abstract: Swimming effort and oxygen consumption of newly emerged green turtle Chelonia mydas hatchlings was measured simultaneously and continuously for the first 18 h of swimming after hatchlings entered the water. Oxygen consumption was tightly correlated to swimming effort during the first 12 h of swimming indicating that swimming is powered predominantly by aerobic metabolism. The patterns of swimming effort and oxygen consumption could be divided into three distinct phases: (1) the rapid fatigue phase from 0 to 2 h when the mean swim thrust decreased from 45 to 30 mN and oxygen consumption decreased from 33 to 18 ml h(-1); (2) the slow fatigue phase from 2 to 12 h when the mean swim thrust decreased from 30 to 22 mN and oxygen consumption decreased from 18 to 10 ml h(-1); and (3) the sustained effort phase from 12 to 18 h when mean swim thrust averaged 22 mN and oxygen consumption averaged 10 ml h(-1). The decrease in mean swim thrust was caused by a combination of a decrease in front flipper stroke rate during a power stroking bout, a decrease in mean maximum thrust during a power stroking bout and a decrease in the proportion of time spent power stroking. Hence hatchlings maximise their swimming thrust as soon as they enter the water, a time when a fast swimming speed will maximise the chance of surviving the gauntlet of predators inhabiting the shallow fringing reef before reaching the relative safety of deeper water.
authors.affiliation: The University of Queensland, Physiological Ecology Group, School of Integrative Biology, Qld 4072, Australia. d.booth@uq.edu.au
authors.forename: David T
authors.initials: DT
authors.lastname: Booth
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000502:physiology*; D001315:Australia; D004734:Energy Metabolism / Q000502:physiology*; D010101:Oxygen Consumption / Q000502:physiology*; D013550:Swimming / Q000502:physiology*; D013997:Time Factors; D014426:Turtles / Q000502:physiology*