here are so many living things - so many ways of living! And, some of them illustrate better than any textbook the long route that life took from molecule to mammal. One of these is the genus Clarias, the 'Walking Catfish'.

They are true fish. But, they breath air!

Their air breathing organ is in their brachial cavity, just like our lungs are. It contains so much air that they often swim as though they were tail-heavy. Their gills have atrophied so much that they suffocate where water freezes over and air is unobtainable. However, they can "walk" on land to move from one water body to another. You've seen those drawings of primitive sea creatures crawling up onto lifeless land - this drawing is alive!

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