I'm not sure what cubic volume vs 2D surfaces means to you, but these comparisons are by mass, not volume. Plus, anaerobic bacteria would only come up on top if you counted all of them as one species, which they are not.
replyPretty much all life is 1 g / ml give or take 20%
replyEven flying animals?
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replyThe same argument could be had for fish, since they inhabit the volume of water, instead of the thin land surface of earth.
replyThey are in zones and layers, yes. But very very thinly spread. Most life in the ocean are withing the top 3 meters.
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