Octopus & Squid

Cuddly creatures with more than two arms

Their apparent problem-solving ability has led cephalopods to be recognised as intelligent.

Do octopuses dream?

Scientists used to think that only mammals and birds experienced different sleep states. More recent research, however, has revealed some reptiles and cuttlefish -- another cephalopod and relative of the octopus -- show non-REM and REM-like sleep.

A new study has found that the octopus has ‘quiet’ and ‘active sleep’, with different episode duration and periodicity, and experiences active sleep after a long episode of quiet sleep.

One of the common cuttlefish in the Marine Resources Center at the Marine Biological Laboratory
One of the common cuttlefish in the Marine Resources Center at the Marine Biological Laboratory

Cuttlefish smart enough to wait for better reward

Using a modified version of the Stanford marshmallow test, researchers at the Marine Biological Laboratory (The University of Chicago) discovered that cuttlefish had the ability to delay gratification for a better reward—and those that were able to do it for a longer duration possessed better cognitive learning abilities.

The findings, which demonstrated the link between self-control and intelligence, was published recently in the Proceedings of the Royal Society B journal.

Cephalopods’ colour-changing skin inspires shape-changing gel

Inspired by this, the engineers at Rutgers University–New Brunswick have developed a 3D-printed smart gel that changes shape when exposed to light, as well as a 3D-printed stretchy material that can reveal colours when the light changes.

A paper on the research has been published in the journal ACS Applied Materials & Interfaces.

Octopuses are highly intelligent creatures.
Octopuses are highly intelligent creatures.

Octopuses seen punching fish

Called "active displacement" of fish, this behaviour usually takes place during collaborative hunting efforts that both the octopus and fish engage in.

In such a situation with multiple parties, a complex network is created where investment and payoff can be unbalanced, and this gives rise to partner control mechanism, said marine biologist Eduardo Sampaio from the University of Lisbon in Portugal. A paper on this behaviour was published in the Ecology journal.

The Octopus, a Friend

Common octopus. Photo by Francesco Turano.

Talking about this animal is simply a pleasure, almost as much as meeting it and relating to it underwater. It is satisfying to spend some time putting my thoughts into words about the octopus, as I am a diver in love with this extraordinary creature—a mollusc that reasons.

Southern California's Market Squid Run

Most years, Southern California on the US west coast is the site of a special marine life aggregation, treating locals to one of the most unique dives in the world. Hundreds of thousands of market squid (<i>Doryteuthis opalescens</i>) swim into recreational dive depths to mate and lay an expansive canvas of egg baskets (collections of eggs) across the sandy substrate.

Giant Australian Cuttlefish

The giant Australian cuttlefish (Sepia apama) is the largest cuttlefish in the world, reaching up to half a metre in total length and weighing in at around 11kg. Solitary animals, they are found all along the coastline of the southern half of Australia—from Central Queensland on the eastern coast, right around the bottom of the continent and up to Ningaloo Reef in Western Australia.

An off-axis pupil and the principle of chromatic aberration (where different wavelengths come to focus at different distances behind a lens) can combine to provide “color-blind” animals with a way to distinguish colors.

Hang on… aren’t they colourblind?

One of the greatest puzzles in biology, to me anyway, is how and why cuttlefish are able to put on their dazzling displays of colour to signal other members of their species and camouflage by closely matching the coloration of natural backgrounds considering they are colour blind.