MALE shrimp undergo a menstrual-like cycle of reproductive readiness and renewal, in which they purge their old, tired sperm and replace them with a fresh lot. It is the first time males have been found to refresh sperm just as females refresh eggs.
Biologists have tended to focus on the more obvious reproductive cycles of females, assuming that nothing similar happens in males – in part because males tend not to undergo dramatic and obvious physiological changes. “The thought is that males are always ready,” says Ernest Chang, a comparative physiologist at the Bodega Marine Laboratory of the University of…
