Small male squid can't beat their bigger rivals when courting a female, so they resort to a sneakier tactic: deploying their sperm at the last moment. After a female chooses a large male, he places his sperm packet inside her oviduct and stays with her until she spawns so that no other male has a chance to mate with her. But smaller males hang out close to the nuptial pair and rush in to mate with her just as she releases her eggs. These diminutive Romeos place packages of sperm on the outside of the female's body, close to her sperm storage organ, just below her mouth. The sperm thus fertilize some of her eggs as she deposits them on the sea floor. Although the sneakier males don't inseminate as many eggs as their rivals do, it is still an effective tactic, researchers report today in BMC Evolutionary Biology. Lab studies also reveal that, despite their size, small squid make bigger sperm than large squid. That's not because the bigger sperm outcompete the smaller ones; instead, they're large because they have to withstand the harsh environment outside of a female's body.
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