Smaller than the head of a pin, this arrow squid (Doryteuthis plei) embryo looks like a miniature adult and is almost ready to hatch! Depending on the squid species, the development from a fertilized egg to a nearly-hatched larva can take one or several weeks. The embryo sits in an egg-sac, which keeps it separate from other developing embryos nearby and provides it food through absorption. Once the yolk sac breaks down—the sac is dissolved by the embryo—the new larvae will drift in the ocean waves as zooplankton. And if it's lucky enough to not be eaten by a predator, it will continue growing into an adult squid. Watch a more detailed video of squid development.