Australia: The Land Where Time Began

A biography of the Australian continent 

Shield shrimp

The eggs of this shrimp lie dormant for years until the rare occasions when sufficient rain falls to form pools in the surface gullies. The first shrimps to hatch are all females, which then produce more eggs without having mated, and succeeding generations of female shrimps continue to lay eggs that always hatch only females. By the time the pools start to dry up males start to hatch. The males mature rapidly and fertilise the eggs of any females producing eggs at that time. When the water in these pools evaporates completely the fertilised eggs dry out and remain dormant until the next sufficiently heavy rain. Under the same circumstances the unfertilised eggs die. 

http://home.vicnet.net.au/~gfnc/articles/shield_shrimp.htm

Sources & Further reading 

Penny Van Oosterzee, 1993, The Centre - The Natural history of Australia's Desert Regions, Reed Australia.