The Water beetle reference article from the English Wikipedia on 24-Apr-2004
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Water beetle

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A water beetle is a beetle adapted for living in water. A number of different types are known, all living in or on fresh water.

Water beetles carry an air bubble underneath their abdomens, which both provides an air supply, and prevents water from getting into the spiracles.

Water beetle larvae are also aquatic, dwelling on the bottom.

Types:

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