Hello, I'm an expert in the field of biology and natural sciences. When discussing the shortest life span, we often think of organisms that have very brief life cycles. Among the various species on Earth, certain insects and microscopic organisms are known for their extremely short lives.

The mayfly is often cited as having one of the shortest adult life spans. Some species of mayflies have an adult life span of less than a day, with some living only a few hours after they emerge from the water as winged adults. However, it's important to note that the larval stage of mayflies can last for months or even years, depending on the species.

Other contenders for the shortest life span include certain types of bacteria and protozoa, which can divide rapidly under favorable conditions, leading to life spans that are measured in hours or even minutes for individual cells.

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Their life lasting only for 24 hours. Mayflies also called as 'one-day insects' because of their shortest life span. There are 2500 different species of mayflies in the world. In fact, some members of mayfly family die within few hours.read more >>