Many male octopuses, to avoid being eaten during mating, will keep their bodies as far removed from the female as possible, extending a single arm with a sperm packet towards her siphon, a manoeuvre known as ‘the reach’. […]
In 1959, Peter Dews, a Harvard scientist, trained three octopuses there to pull a lever to obtain a chunk of sardine. Two of the octopuses, Albert and Bertram, pulled the lever in a ‘reasonably consistent’ manner. But the third, Charles, would anchor his arms on the side of the tank and apply great force to the lever, eventually breaking it and bringing the experiment to a premature end. Dews also reported that Charles repeatedly pulled a lamp into his tank, and that he ‘had a high tendency to direct jets of water out of the tank; specifically … in the direction of the experimenter’. ‘This behaviour,’ Dews wrote, ‘interfered materially with the smooth conduct of the experiments, and is … clearly incompatible with lever-pulling.’ […]
Both female and male octopuses mate only once, and enter a swift and sudden decline into senescence soon after, developing white lesions on their skin, losing interest in food, and becoming unco-ordinated and confused. The females die from starvation while they tend their eggs, and the males are typically preyed on as they wander the ocean aimlessly. […] In its early evolutionary history, the octopus gave up its protective, molluscan shell in order to embrace a life of unboundaried potential. But the cost was an increased vulnerability to toothy and bony predators. An animal with a soft body and no shell cannot expect to live long, and so harmful mutations that take effect only once it has been alive for a couple of years will soon spread through the population. The result is a life that is experientially rich but conspicuously brief.
Amia Srinivasan, The Sucker, the Sucker!, London Review of Books, Vol. 39 No. 17, 7 September 2017, pages 23-25
Added to diary 16 March 2018