These are called in Japan; haiiro means gray. I want to say that they cannot keep on living except dirtiness rather than the toughest water beetle to dirtiness. I can often find them even if it's environment which is dirty and other living things cannot living. And moreover, they swim so fast and active. They are almost always moving. I also want to say that they can swim most brisk in the all of water beetles. Stranger or so. | |||||||
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