In a river of southern Africa, a “large”-mouthed creature swam along the rocks looking for its next meal. Something about the “slender” animal caught the attention of snorkelers — and for good reason.

The amount of sperm released decreased sharply with each mating during a single day, reducing the males' fertilization rate.

They found that male medaka can mate 19 times per day on average. In the first three mating sessions, the medaka released ...

When Jimmy Carter returns to Plains, Ga., a final time after his state funeral in Washington on Jan. 9, America will bury not ...