https://jeltsch.org/en/tags/tissue-drainage/Recent content in Tissue Drainage on Michael’s DomainHugoen-usCopyright © 2002 - 2026 Michael Jeltsch.Fri, 24 Jul 2026 00:18:18 +0300https://jeltsch.org/en/fish/Fri, 28 Jun 2024 00:00:00 +0000https://jeltsch.org/en/fish/<p>Fish are breathing with their gills, but this is literally, for many of them, only half of the story. The difficulty of extracting oxygen from water is the single most defining force that shapes fish evolution. Land animals are mostly exposed to the same oxygen concentration, but fish need to operate in waters of vastly different and rapidly changing oxygen content. Moreover, water contains much less oxygen than air, and the diffusion of oxygen in water is magnitudes slower than the diffusion of oxygen in air. Therefore, fish evolution was forced to come up with creative ways to</p>