Do large predatory fish track ocean oxygenation?

  title={Do large predatory fish track ocean oxygenation?},
  author={Tais W. Dahl and Emma U Hammarlund},
  journal={Communicative & integrative biology},
  volume={4 1},
The Devonian appearance of 1-10 meter long armored fish (placoderms) coincides with geochemical evidence recording a transition into fully oxygenated oceans.1 A comparison of extant fish shows that the large individuals are less tolerant to hypoxia than their smaller cousins. This leads us to hypothesize that Early Paleozoic O(2) saturation levels were too low to support >1 meter size marine, predatory fish. According to a simple model, both oxygen uptake and oxygen demand scale positively with… CONTINUE READING