Image of the Day: Self-Insemination

ABOVE: Spawning Japanese pygmy squid attaching eggs to a blade of seagrass
EIJI FUJIWARA

Reproductive biologists can have a hard time figuring out how sperm reach eggs when females of some species store the sperm for later use. Now, researchers have caught a female Japanese pygmy squid (Idiosepius paradoxus) in the act. The squid inseminates her eggs one at a time using very little sperm. She cradles an egg in the arm crown from which her arms extend and attaches the egg to a surface, such as seagrass, then fertilizes it by placing her sperm-storage organ over it. The scientists published their observations in Current Biology on January 21. 

Y. Iwata et...