By Susan Milius
After death, male guppies can keep on siring offspring because females store sperm for so long. As a result, a living male in a stream in Trinidad can end up competing with long-gone fish from his grandfather’s generation.
At its most posthumously successful, stored ghost sperm sired about one in four of the offspring among wild guppies released into a stream, evolutionary biologist Andrés López-Sepulcre of École Normale Supérieure in Paris and his colleagues report June 5 in Proceedings of the Royal Society B.