Octopus—An Alien in the Ocean
Three hundred million years ago, in the ancient oceans of a young Earth, a creature with eight arms, two eyes, and an ink sac began its journey through evolution. On its way, it inspired innumerable renowned tales of fiction, as well as futuristic innovation in fields of technology. It slithered into Minoan Art and inspired the terrifyingly powerful Gorgon of Greek Mythology. Its likeness, the Kraken, wreaked havoc on seafarers. It also plays an essential role in Victor Hugo’s ‘Toilers of the Sea’, and even encounters James Bond!
While the octopus continues to spread its tentacles across the fictional world, the modern planet we live in seeks inspiration from these alien-like creatures in several technological and scientific endeavours. The octopus gives insights into complex fields of study such as cellular neurobiology and is a goldmine for technology involving camouflage and defence strategies. It may hold the key to space exploration, regenerative medicine and possibly Marvel’s aircraft cloaking technology. Despite being an invertebrate—animals thought to be structurally inferior to those with spines—several of the creature’s physiological aspects compare to those of highly developed vertebrates. As a result, researchers have taken a key interest in the octopus with advances being made in understanding its brain, regenerative capabilities and its camouflaging abilities.
The Eight-Legged Intellectual
Humans are social animals. We attribute intelligence to creatures that form relationships and interactions among their species. As a result, socially inclined creatures such as elephants are labelled exceptionally intelligent. Octopuses, however, lead solitary lives, venturing out only to mate, after which they die. It was thus believed for a very long time, that octopuses lacked intelligence—Aristotle drew attention to this characteristic in his book ‘History of Animals’. Their intellectual prowess, however, lies not in their socialising potential but rather in their cognitive abilities.
In 2016, Inky the octopus, astounded all, as he disappeared from New Zealand’s National Aquarium. He escaped his enclosure through a small opening, slid across the floor, and squeezed out of a drainpipe into the ocean. Rob Yarrell, the Manager of the National Aquarium, was convinced that Inky’s curious nature had made him venture into the unknown.
Across the world, in Germany, when an aquarium was closed for the winter, its resident octopus was reasonably bored. As a result, he repeatedly squirted a lightbulb with water, eventually short-circuiting the lights in the entire building. He also resorted to juggling hermit crabs, throwing rocks at the glass, and ‘redecorating’ by moving things around his enclosure.
Inky and his German counterpart, among others of their species, prove to the world that octopuses are more than socially inept creatures. Unlike other organisms, their power of understanding is not limited to foraging, sleeping and procreation. Instead, their intelligence, as seen in the way they behave, raises questions on the functioning of the minds of these creatures and close studies of their genetic makeup reveal secrets on the computing power of these molluscs.
Inspiring Robotic Innovation
Sequencing the octopus’ genome revealed a gene group, protocadherin, supposedly found only in vertebrates. It enables the development of neurons and their short-range interaction. The octopus has 168 of these genes—twice that of mammals. Of its half a billion neurons, two-thirds spill out from its complex, unusually large brain, to its arms, without the use of vertebrate spinal cords. Each arm has independent computing power—they can carry out cognitive tasks even when dismembered. This finding has caused a collaboration between neurobiologists and roboticists in the sub-field of soft robotics.
Here, robots are constructed using highly compliant materials, imitating the movements and reactions of living organisms. This finds extensive use in intrusive surgery, the building of exoskeletons to assist patients, and in collaborative robots—those that work safely near humans. Another fascinating application of this concept is in biomimicry, wherein soft robots can be used to mimic sea creatures that can efficiently manoeuvre through water. Such a project was attempted by a Cornell University team in 2015, under NASA’s Innovative Advanced Concepts grant. The team designed a soft robot to mimic a lamprey or cuttlefish in movement underwater, in order to explore the ocean below Jupiter’s icy moon, Europa.
The large number of neurons in the arms of an octopus guarantees the creature’s viability for some time, even in the likely event of being dismembered. As a result, the loss of an arm would entail the loss of several neurons—not an ideal scenario for the octopus. Evolution, however, has granted the creature the ability to regenerate a fully functional arm, complete with neurons and suckers, avoiding the former dilemma.
A Master of Reconstruction
Imagine a world where every physical injury is repairable, complete with perfectly functioning nerve endings and tissue. In this Utopian world, humans can regrow severed limbs, repair diseased or lost tissue and thus prolong the longevity of their anatomy.
The growth and differentiation of cells in the human body takes place through special chemicals. Acetylcholinesterase (AChE), present in brain synapses and other nervous system intersections, is one such substance that plays a role in cell proliferation, differentiation and death. While octopuses lack the complexities of human physiology, the chemical is unusually active in these organisms.
This finding caused researchers to study six healthy common octopuses—they were anaesthetised and a small tip from each arm was removed. Once the animals awoke, everything appeared normal except for changes in their internal biochemistry. In a span of three days, a “knob” covered with undifferentiated cells, formed on the cut tips. By the second week, a “hook-like structure” with a mass of stem cells and blood vessels was visible. Within the next hundred-odd days, the arm tip resembled the original cleaved end.
A study of the tissue revealed AChE flood into action after a couple of weeks. Once the limbs had fully regenerated, it was back to normal levels. According to researchers, the AChE protein could be a potential component in promoting or regulating regrowth. A study of the chemical in various phases of regeneration could lead to a giant leap for mankind in the field of regenerative medicine. Several questions can be asked on the choice of using an octopus as a model for studying regeneration. Smaller and readily available creatures such as lizards and starfish would make for a smarter choice for experimentation. However, unlike the inferior regrown limbs of these creatures, those of an octopus, once regenerated, are as good as new.
Although the octopus proves to have superior intellect and regenerating abilities, it is not limited to its cognitive and cell proliferation gifts. The octopus has the unusual but powerful ability of camouflage, making full use of it in its deep and dark world of sea predators.
Camouflage—A Play of Light and Colour
The octopus is a master of disguise, in the art of camouflage, to be precise. It has three specialized mechanisms—chromatophores which are small sacs of different coloured pigment that contract and expand, changing the animal’s overall hue; Irridophores that reflect light and lend further colouring, and Leucophores which are white cells that provide the perfect background. Muscles under the skin complete the picture by giving it the required texture.
The octopus, unlike the popular colour changing reptile chameleon, does not entirely depend on colour switching tactics for its camouflage. The creature also has the ability to manipulate light, giving the definition of camouflage a whole new meaning. A bizarre, but unknown fact is that octopuses are believed to be colour-blind. This has raised quite a few questions such as doubts pertaining to the creatures ability to sense colour and if they can see shades that the human eye cannot perceive.
In 2014, inspired by the octopus’ camouflaging techniques, engineers at the University of Illinois built a flexible material that consists of a grid of 1mm cells, a temperature-driven dye that switches colour on command and changes colour to match its surroundings. Although it only responds in black-and-white, the team hopes that it will have commercial and military applications.
Furthermore, in 2017, researchers at Cornell University developed a method to morph 2D surfaces into 3D shapes on demand. The leader of the project, Rob Shephard, was inspired by the octopus’ ability to change its skin texture to match the object it camouflaged against. Their method involves the use of a rigid mesh, laser cut in a way that when attached to a stretchable material, would constrain the material to form targeted shapes when inflated. Future work aimed to focus on the ability to change colour as well as texture, and to create more precise shapes with higher-resolution laser patterning.
The octopus is a tough beast to grasp. Its eight appendages, three hearts, camouflaging skills, and immense brainpower often made scientists wonder if the ancient Greeks were right in believing that life on earth came from the stars. The octopus inspired myths and legends in the past. Today, it encourages scientific advances in the core fields of medicine, defence, and material science while also contributing to developments in space travel. While the burning question of whether the octopus holds secrets to extraterrestrial life might keep us at bay, we can agree that the octopus is a creation of marvel that still continues to inspire the world, both artistically and technologically.
Featured Image Credits: reddit