Sex at arm’s length? Male octopuses use specialised arm to mate, scientists find

Scientists remain unclear about how the hectocotylus detects a mate, or delivers sperm to the right location. Photograph: Alexis Rosenfeld/c/o Visa Pour L'Image Perpignan

Sex might seem an intimate act, but scientists have shed fresh light on how octopuses manage it at arm’s length.

Male octopuses use a specialised arm called the hectocotylus to place a package of sperm inside the female’s reproductive system.