}

Joints without bone

2006/04/20 Roa Zubia, Guillermo - Elhuyar Zientzia

The octopus has no bones. Flex your arms to your liking, but often move each arm as if you had three joints. German and Italian biologists investigate how octopus make these false joints. The response is in the muscles: the octopus contracts a part of the muscle and is able to move that contraction through the arm as if it were a wave; the area in which both waves are found behaves precisely as a joint.

Photo: Binyamin Hochner