Most invertebrates have no internal air sac breathing organ. Arachnids kinda do, and I’m seeing something about semi-aquatic snails, but direct diffusion is pretty efficient at that scale.
Axolotls have them despite not needing them because they can live just fine without ever inhaling air for their entire life. But they sometimes do it for fun and then blow out bubbles.
Most invertebrates have no internal air sac breathing organ. Arachnids kinda do, and I’m seeing something about semi-aquatic snails, but direct diffusion is pretty efficient at that scale.
Axolotls have them despite not needing them because they can live just fine without ever inhaling air for their entire life. But they sometimes do it for fun and then blow out bubbles.
Amphibians are the weirdest vertebrates.
Looking at my axolotl that is currently trying to pretend to be a plant, yep.