The ink cloud emitted by an octopus when threatened aids escape because it resembles the shape of the octopus.

“When their speed alone is not enough for safety, [cuttlefish] squirt a
cloud of dense, dark coloured ink that is synthesised in their bodies.
This ink surprises their predators for a few seconds, which is usually
enough for them to escape.” (Yahya 2002:104)

“Sometimes the ink cloud itself resembles the blobby shape of an octopus and acts as a decoy, allowing the octopus to escape while the predator eyes the blob.” (Crump 2005:109)

Crump, M. 2005. Headless Males Make Great Lovers & Other Unusual Natural Histories. University of Chicago Press, Chicago, IL. 199 pp.
Yahya, H. 2002. Design in Nature. London: Ta-Ha Publishers Ltd. 180 p.

Last Updated August 18, 2016