> The maturation of the reproductive organs appears to be driven by secretions from the optic gland. These same secretions, it seems, inactivate the digestive and salivary glands, which leads to the octopus starving to death.
> In 1977, researchers removed this gland and found that the octopus' mothering instincts disappeared. She abandoned her eggs, started feeding again, and went on to live a much longer life.
As a reproductive strategy for an (arguably) intelligent animal ... this makes me feel sad. However there's plenty of octopuses around so in evolutionary terms it's a strategy that works.
As for the males - and this is the point at which my anthropomorphic 'yuk' reflex goes into overdrive - they die soon after their first successful sexual encounter. Males store sperm in one of their arms. For some species, 'sex' involves detaching that arm and giving it to the female to keep for later use. Then they wander off and die. Possibly from disappointment.