Image of sperm hooks (<em>Peromyscus maniculatus</em>)
The Mystery of the Mouse Sperm Hook
Nearly all mouse sperm have hooks on their heads. But new research suggests the structures slow them down—so what exactly is their purpose?
The Mystery of the Mouse Sperm Hook
The Mystery of the Mouse Sperm Hook

Nearly all mouse sperm have hooks on their heads. But new research suggests the structures slow them down—so what exactly is their purpose?

Nearly all mouse sperm have hooks on their heads. But new research suggests the structures slow them down—so what exactly is their purpose?

ABOVE: Heidi Fisher
sperm competition
A headshot of Matthew Gage
Evolutionary Ecologist Matthew Gage Dies at 55
Amanda Heidt | Apr 20, 2022
The University of East Anglia researcher was best known for his contributions to the study of sexual selection, particularly post-copulatory sperm competition.
Image of the Day: The Long and Short of It
Sukanya Charuchandra | Aug 20, 2018
For flycatchers, the attractiveness of male birds is tied to the length of their sperm.
Scientists Solve Giant Sperm Paradox
Tanya Lewis | May 26, 2016
A study reveals why some male fruit flies produce sex cells that are 20 times the length of their bodies.
The Hidden Side of Sex
Patricia L.R. Brennan | Jul 1, 2014
Sexual selection doesn’t end when females choose a mate. Females and males of many animal species employ an array of tactics to stack the deck in their reproductive favor.