Random Thought #70

Awhile back, I wrote about fishes and why they have gills and how they work. My sister-in-law and her family has a small aquarium in their apartment and it never dawned on me before, but I wondered why aquariums constantly have bubbles blowing in their tank. Now after reading about gills ,I understand that in aquariums, there is no exposure to open air or a large amount of water, so oxygen has to be pumped into the water so that the fish can breathe. Ever wonder why little orange goldfish that they give away to people at the carnival die so soon? Most likely...asphyxiation.