Proteins that synthesize, bind, and degrade endocannabinoids are present in the body’s sperm factories, suggesting that the use of cannabis may directly affect them.

Groups of corals release all of their eggs and sperm once a year, but the timing of their spawning is under threat from climate change.

Scientists track the movement of sperm flagella.

Asexual female nematodes use their male offsprings’ sperm to fertilize eggs, but cast away their genes.

Videos reveal how a female squid fertilizes her eggs—one at a time and without spilling much stored sperm.

For flycatchers, the attractiveness of male birds is tied to the length of their sperm.

The artificially motorized cells may one day help fight cancers in the female reproductive tract.

A project aims to preserve samples of the climate change–vulnerable animals for future restoration.

Mary Hagedorn is racing to save Earth’s coral reefs by developing techniques for freezing the colonial animals’ gametes.