Dead, live guppies vie for paternity
Females can use sperm months after mates go belly up
Among wild guppies in Trinidad streams, a female (left) can store sperm from a male (right). In a new experiment, female Trinidadian guppies lived much longer than males and still used sperm left over from the generation of the grandfathers of current males.
Paul Bentzen/Dalhousie
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.
Biologists have long known that female Poecilia reticulata guppies store sperm. The cells clump in little pockets in a female’s ovarian cavity and feed on sugars released by ovarian tissue. Storage in itself isn’t unusual, López-Sepulcre says. Some crabs, turtles, lizards, bats and other creatures preserve sperm for later use.
