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Anatomical Evidence for a Counter-current Heat Exchanger in the Leatherback Turtle (Dermochelys coriacea)


FRAIR et al.1 have recently given strong circumstantial evidence that leatherback turtles (Dermochelys coriacea) can maintain a deep body temperature at least 18° C higher than the ambient temperature of cold water. The mechanisms underlying this differential are largely unknown but are presumed to be muscular activity combined with the thermal inertia of a large body mass and an insulating layer of subepidermal fat1. Countercurrent flows have also been suspected as a heat retention mechanism1–2 but so far have not been proved. We now present anatomical evidence for a countercurrent heat exchanger in the front and rear flippers of a leatherback turtle, which is the first evidence for this kind of heat retention mechanism in a reptile.

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  1. 1

    Frair, W., Ackman, R. G., Mrosovsky, N., Science, 177, 791 (1972).

  2. 2

    Mrosovsky, N., and Pritchard, P. C. H., Copeia, 624 (1971).

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