MrsDewwBerry
said
:
The shortest living animal in the world is the Mayfly. Its entire adult lifespan is just 24hrs.
Indeed! Though that is the lifespan of the imago (adult form) specifically; the aquatic nymph (larval) form lives for up to one to two years. It is still the shortest-lived animal in the world!
This strategy does work evolutionarily, though! The mayfly is understood to be the oldest surviving winged insect on Earth, about 300 million years ancient.