According to the University of California’s Museum of Paleontology, cephalopod reproduction differs greatly from the reproductive strategies of most other mollusks. Most cephalopods exist as discrete male or female entities, rather than being hermaphroditic as many simple mollusks are.
Before fertilization takes place, most cephalopods engage in elaborate courtship rituals. These rituals may include choreographed movements and drastic color changes. Once the female has accepted the male’s advances, he deposits a spermatophore into her mantle or body cavity. This spermatophore transfer often occurs with the help of a penis, but some species use a tentacle instead. Some species have a highly modified tentacle that serves this purpose, called a hectocotylus. In many species, the hectocotylus detaches and remains inside the female.
Many cephalopods, such as cuttlefish and nautiluses, die after breeding. Others, such as octopuses, brood their eggs for some time before dying. Most of the group of octopus eggs hatch before the mother dies. Some of the smaller species only live for about one year, while the largest pelagic squid species live for about seven years. A short time later, the female deposits the eggs in clusters on a hard surface. The young cephalopods hatch out into miniature versions of the adults.