SEVENSEAS Marine Conservation & Travel Issue 22, March 2017 | Page 75

1 Topic : 5 Facts

How well do you know the ocean?

This regular feature will help acquaint you with our blue planet.

Topic: Cephalopods

Octopus are in the phylum Mollusca along with snails, clams, squid, and chiton. However, they do not have an internal or external shell like their cousins. The only hard part on an octopus is its mouth, or beak!

To escape from a predator an octopus will often release a jet of ink. This ink is concentrated melanin, the same pigment we have in our skin and hair!

All octopus are venomous! Although the blue ringed octopus, native to the Indo-Pacific, is the most deadly, the saliva of all octopus species is poisonous making them interesting to observe, but never to handle.

The largest, and longest living, octopus is the giant Pacific octopus (Enteroctopus dofleini). The largest specimen found was more than 9 meters across, that’s 30 feet!

Octopus, and other members of the class Cephalopoda, are considered the most intelligent of all invertebrate species, able to learn and problem solve.

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SEVENSEAS - 75

March 2017 - Ocean Literacy