An interesting article based on personal experience with octopuses in a public aquarium and personal diving adventures. Many statements are definitely NOT about all species and a few disagree with other documents but the article is a nice introduction to octopuses and well worth the read.
Inkfishes (cephalopods) are fascinating creatures of the oceans because they have evolved from a very distant past, into forms that have many arms, excellent eye sight, an acute sense of smell and well developed brains. Today they are thought of as molluscs (soft-bodied) even though they do not resemble any of the typical molluscs of today, such as shells, clams and nudibranchs. In this article we'll have a close look at the most common shallow water inkfishes of New Zealand, in particular the brainy and handy octopus.