Ecological and evolutionary correlates of metabolic capacities in anuran amphibians

1. Ecological and evolutionary correlates of metabolic capacities in anuran amphibians

2. Metabolic capacities in vertebrates • Aerobic capacity is the maximum rate of oxygen consumption during vigorous, exhaustive exercise. Generated principally by the sustained contraction of oxidative muscle fibers and measured as VO2max. • Anaerobic capacity is the maximum rate of energy production from anaerobic glycolysis during exercise. Generated principally by the power contribution of glycolytic muscle fibers and estimated by the accumulation of lactic acid.

3. Functional correlates of inter- and intra-specific variation in metabolic capacities • Ecological--predict or account for patterns of distribution and activity • Evolutionary--contribute to an understanding of the evolutionary origin of complex physiological structures (oxidative fibers) and processes (endothermy)

4. Natural History of American Toads

5. Measurements of VO2rest and VO2max

6. Exhaustive locomotor exercise

7. Development of aerobic capacity and dispersal in toads

8. Body mass at dispersal

9. Behavioral correlates of inter-specific variation in metabolic capacities Study included 17 species of frogs and toads from around the world, representing broad ecological, morphological, and behavioral ranges

10. Metabolic variation among species

11. Ambush foragers--high anaerobic capacity

12. Burrowing/active foragers--high aerobic capacities

13. Aerobic capacity model for the evolution of endothermy • Proposed by Bennett and Ruben, 1979 • Focus of selection for metabolic physiology is on activity, not temperature • High aerobic capacities correlate with endurance and stamina • High aerobic capacity for exercise is functionally linked to resting or basal metabolism

14. VO2rest and VO2max among 17 anuran species

15. Correlation between resting and activity metabolism in frogs

16. Dart poison frogs & a coqui

17. Coqui of Puerto Rico (and Hawaii, regrettably)

18. Metabolic characteristics of Dart poison frogs

19. Foraging behavior and metabolic characteristics

20. Bocas del Toro, Panama Remote chain of islands in the Caribbean, located between Costa Rica and Panama

22. Red (Isla Bastimentos) andGreen (Isla Colon) Frogs of Bocas

24. The Bocas del Toro “Experiment in Nature” may be over

25. Wells and Taigen and UConn Physiological Ecology Class Reproductive behavior and aerobic capacities of male American toads (Bufo americanus): Is behavior constrained by physiology?

26. No, at least not that night

27. Metabolic costs of vocalization

28. Measurement of VO2calling Repeated gas samples taken from enclosed metabolic chamber while animals are stimulated to call. The microphone records vocal behavior and calling activity

29. Oxygen consumption while calling in Spring peepers

30. Comparison of VO2calling with VO2 during exhaustive locomotor exercise in Spring peepers

31. Calling Muscles in Frogs

32. Comparison of male and female trunk muscles in Spring peepers

33. Enzyme profiles of muscles used in calling

34. VO2 during locomotor exercise and citrate synthase activity

35. Citrate synthase in vertebrate muscles

36. Does individual variation in CS activity correlate with calling behavior? Yes, in a complicated way…

37. Comparison of low and high-calling male Spring peepers

38. Physiological/biochemical correlates of calling behavior

39. Factors correlated with calling rate