Octopus & Squid

Cuddly creatures with more than two arms

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.

Octopuses that live deeper in the ocean have bumpier skin

Scientists from the Field Museum in Chicago, USA recently discovered that Pacific warty octopuses don’t all have the same appearance, nor do they all live at the same ocean depth.

Their findings, which was published in the Bulletin of Marine Science, indicated that the bumpier the octopus’ skin was, the deeper in the ocean they would be found.

In their research, the team examined 50 Pacific warty octopuses from the Northeast Pacific Ocean, as well as specimens from the University of Miami Marine Laboratory and the California Academy of Sciences.

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 (Doryteuthis opalescens) swim into recreational dive depths to mate and lay an expansive canvas of egg baskets (collections of eggs) across the sandy substrate.

Researchers use squid ink to diagnose gum disease

To diagnose gum disease, dentists insert a thin metal probe between the tooth and gum to measure the amount of gum that has shrunk back from the tooth. The depth to which the tool can be inserted indicates the severity of the gum disease.

Apart from being invasive and uncomfortable, this method of diagnosis is sometimes painful for the patient. In addition, the measurements are viable, as the probe can measure only one portion of the tooth at a time.

Enter Jesse Jokerst.

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.

Cuttlefish are capable of changing colour and pattern (including the polarization of the reflected light as well as the texture of the skin.

Cuttlefish can go into electric stealth mode

Sharks home in on faint bioelectric fields generated by the bodies of their prey which they pick up using sensitive detectors on their snouts.

When researchers from Duke University showed captive cuttlefish held in a tank videos depicting the menacing silhouettes of a shark or predatory grouper fish they reacted by lowering the electric field dramatically. Being shown the shadow of a harmless crab produced no reaction.

Chambered nautilus

Vanuatu: A Dive with a Living Fossil at Penama Island

Look up a chambered nautilus in a book or on the web will reveal they are in the same class of mollusks as octopuses, squid and cuttlefish. The first thing that sets this cephalopod apart from the rest of the group is that the nautilus date back more than 500 million years, and were once the dominant form of life in the ocean. And to share a night dive with one of these true living fossils is a very fortunate event.

Common Octopus

New study deciphers octopus locomotion

Researchers from Jerusalem’s Hebrew University have filmed crawling octopuses to learn how the animals utilized their flexible arms when they move. Until now, scientists have struggled to understand how their elaborate crawling movements are coordinated. The answer proved remarkably simple: they just choose which arm to use to push themselves along without a trace of rhythm.