Argonauta argo is a species of octopus. Members of family Argonautidae are known for their acute sexual dimorphism, females with webbed dorsal arms capable of secreting calcareous egg cases, and dwarf males with hectocotylized third arms used for fertilization. A. argo resides in epipelagic tropical and subtropical waters and can utilize jetting, thigmotactic means, or possibly air bubbles within egg cases to remain buoyant. These animals often form associations with gelatinous marine species, utilizing them for food, locomotion, and protection. Like other octopuses, defense strategies of A. argo include camouflage and inking. Mating differs from most other octopuses in that A. argo females continue to grow and reproduce after spawning while males die after the loss of their third arm. Females can be fertilized by more than one hectocotylus over successive days by storing them in her mantle cavity. This results in eggs of multiple developmental stages within a single egg case. Egg cases sometimes wash ashore in mass strandings along coastlines, yet live argonauts are rather illusive. Lack of frequent contact with A. argo has resulted in a scarcity of information on the species.