Giant Squid - Reproductive Cycle

Reproductive Cycle

Little is known about the reproductive cycle of giant squid. They are thought to reach sexual maturity at about three years old; males reach sexual maturity at a smaller size than females. Females produce large quantities of eggs, sometimes more than 5 kg (11 lb), that average 0.5 to 1.4 mm (0.020 to 0.055 in) long and 0.3 to 0.7 mm (0.012 to 0.028 in) wide. Females have a single median ovary in the rear end of the mantle cavity and paired, convoluted oviducts, where mature eggs pass exiting through the oviducal glands, then through the nidamental glands. As in other squid, these glands produce a gelatinous material used to keep the eggs together once they are laid.

In males, as with most other cephalopods, the single, posterior testis produces sperm that move into a complex system of glands that manufacture the spermatophores. These are stored in the elongate sac, or Needham's sac, that terminates in the penis from which they are expelled during mating. The penis is prehensile, over 90 cm (35 in) long, and extends from inside the mantle.

How the sperm is transferred to the egg mass is much debated, as giant squid lack the hectocotylus used for reproduction in many other cephalopods. It may be transferred in sacs of spermatophores, called spermatangia, which the male injects into the female's arms. This is suggested by a female specimen recently found in Tasmania, having a small subsidiary tendril attached to the base of each arm.

Postlarval juveniles have been discovered in surface waters off New Zealand, with plans to capture more and maintain them in an aquarium to learn more about the creature.

Read more about this topic:  Giant Squid

Famous quotes related to reproductive cycle:

    In the nineteenth century ... explanations of who and what women were focused primarily on reproductive events—marriage, children, the empty nest, menopause. You could explain what was happening in a woman’s life, it was believed, if you knew where she was in this reproductive cycle.
    Grace Baruch (20th century)