Our recorders in Mtende village, Zanzibar, measured this nine-legged male big blue octopus, Octopus cyanea!

It’s a very exciting find! Nonapus do occur occasionally, but we can’t see any other records of nine-legged Octopus cyanea, perhaps this is the first one recorded?! We’ve measured more than 200,000 octopus in Zanzibar and this is our first!

In this case one arm is bifurcated, meaning it’s divided into two branches. It’s believed this occurs when there is a mutation in one of the Hox genes involved in the development of limbs and organs. Interestingly, the arm that is bifurcated is the male octopus’ hectocotylus (it’s sex organ). One branch of the arm appears to be fully formed and the second partially formed.

Our nonapus is currently being stored in a freezer – hopefully we can arrange for scientists at SUZA to study its genetics!