Continuing on yesterday’s post, people drown and suffocate in water because of certain reasons. Why, then, do fishes survive just fine in water, but suffocate when you leave them on dry land? Well, let me ask you, have you seen a fish’s gills before? Go and look at it. See, a fish’s gills are made out of filaments that are supported in the water, helping the fish get the oxygen they need from the water as they swim around, however, given that they are supported by water, when you take them out of the water, they’ll collapse. It’s kind of like when you leave the swimming pool and your hair instantly sticks to your head, when in the water, they were voluminous and spread out. Thus, out of the water, after the structure has collapsed, the amount of surface area is greatly reduced and their oxygen intake is lessened. The bigger reason that the fishes would die, though, is that their gills would dry out. As mentioned previously, the oxygen needs to be dissolved before it can be diffused through the respiratory surface, and, as the fishes had always been in a wet environment that keeps their gills drenched for them, out of that environment, they have no mechanisms to help them keep their gills wet to allow them to intake oxygen. Hence, as their gills slowly dry out, they get lesser and lesser oxygen, resulting in them slowly suffocating. It’s dehydration that’s actually killing the fishes, in that sense, as the dehydration results in them being incapable of breathing. So, there you go, the reason fishes suffocate on dry land.