The reproduction cycle of the squid is unique as the female dies soon after her off springs hatch because she is too weak to defend herself against her enemies.  The male squid octopus uses a specialized arm called a hectocotylus to transfer sperm to the mantle cavity of a receptive female's pallial cavity. The female lays strings of fertilized eggs on the roof of her den which she guards, cleans and aerates with water expelled from her siphon until hatching—anywhere from 30 days to a year, totally depending on the species of the squids.

The female may build a wall of rocks to seal off the den and will remain in the den until just before she dies, after the eggs have hatched. Squids often mate in large groups, attaching their egg capsules to the ocean floor or maybe to seaweed. Mostly adult octopuses and squids die after reproducing. Their bodies are recycled in the food web, nourishing other animals, and ultimately providing food for their young when they hatch.