We named him Squirt – not because he was the smallest of the sixteen squids in the pool, but because anyone who had the nerve to scoop him into a separate tank to study him would probably get soaked. Squirt had a notoriously precise aim.
As a comparative psychologistI’m used to attacks from my subjects. I have been stung by bees, pinched by crayfish and abused by indignant pigeons. But somehow it felt different with Squirt. As he looked at us its W-shaped pupilsit looked like he was clearly plotting against us.
Of course I’m anthropomorphic. Science does not yet have the tools to confirm whether cuttlefish have an emotional state or whether they are capable of conscious experiences, let alone sinister plots. But there is undeniably something special about cephalopods – the class of invertebrates that live in the ocean and to which cephalopods belong. cuttlefish, cuttlefish and octopus.
As researchers learn more about the cognitive abilities of cephalopods, there are calls to treat them in ways that better match their intelligence levels. California and Washington both mention approved a ban on octopus farming in 2024. Hawaii does considering similar actionand a ban on farming octopus or importing farmed octopus meat has been introduced in Congress. A planned octopus farm in Spain’s Canary Islands is attracting a lot of attention opposition from scientists And animal welfare advocates.
Critics offer There are many arguments against growing octopuses for foodincluding possible releases of waste, antibiotics or pathogens from aquaculture facilities. As a psychologist, however, I consider intelligence to be the most intriguing part of the equation. How smart are cephalopods really? After all, it is legal to keep chickens and cows. Is an octopus smarter than, for example, a turkey?
A large, diverse group
Cephalopods are a broad class of molluscs that also includes the coleoids – squid, octopus and squid – as well the chamber nautilus. Coleoids range in size from adult squid only a few millimeters long (Idiosepius) among the largest living invertebrates, the giant squid (Architeuthis) And colossal squid (Mesonychoteuthis) that can grow to more than 40 feet long and weigh more than 1,000 pounds.
Some of these species live alone in the virtually featureless darkness of the deep ocean; others live socially on active, sunny coral reefs. Many are experienced hunters, but some feed passively on floating debris. Because of this enormous diversity, the size and complexity of cephalopod brains and behavior also vary greatly.
Almost everything known about cephalopod cognition comes from intensive study of just a few species. When assessing the welfare of a particular species of captive octopus, it is important to be cautious about using data collected from a distant evolutionary relative.
Marine biologist Roger Hanlon explains the distributed structure of cephalopod brains and how they use that neural power.
Can we even measure extraterrestrial intelligence?
Intelligence is terribly difficult to define and measure, even in humans. The challenge grows exponentially when studying animals with sensory, motivational, and problem-solving skills that differ profoundly from our own.
Historically, researchers have tended to focus on whether animals think like humans, ignoring the abilities that animals may have that humans do not. To avoid this problem, scientists have tried to find more objective measures of cognitive skills.
One option is a relative measure of size from brain to body. The best studied octopus species, Octopus vulgaris, has about 500 million neurons; which is relatively large for its small body size and comparable to a starling, rabbit or turkey.
More precise measurements may include the size, number of neurons, or surface area of specific brain structures considered important for learning. While this is useful in mammals, an octopus’ nervous system is built completely differently.
More than half of the neurons in Octopus vulgarisabout 300 million, are not in the brain at all, but are distributed in “mini-brains”, or ganglia, in the arms. Within the central brain, most of the remaining neurons are dedicated to visual processing, leaving less than a quarter of the neurons for other processes such as learning and memory.
In other species of octopus, the general structure is similar, but the complexity varies. Wrinkles and folds in the brain increase its surface area and can improve neural connections and communication. Some species of octopuses, particularly those that live in reef habitats, have more wrinkled brains than those who live in the deep seasuggesting that these species may possess a higher degree of intelligence.
Waiting for a better snack
Because brain structure is not an infallible measure of intelligence, behavioral tests can provide better evidence. One of the very complex behaviors that many cephalopods exhibit is visual camouflage. They can open and close small sacs just under their skin that contain colored pigments and reflectors, making specific colors visible. Octopus vulgaris has up to 150,000 chromatophores, or pigment sacs, in one square centimeter of skin.
Like many cephalopods, the common squid (Sepia officinalis) is believed to be color blind. But it can use its excellent vision to produce a dizzying array of patterns over his body as camouflage. The Australian giant squid, Sepia apamauses its chromatophores to communicate, creating patterns that attract mates and deter aggressors. This skill can also be useful for hunting; Many cephalopods are ambush predators that blend into the background or even lure their prey.
However, the hallmark of intelligent behavior is learning and memory – and there is ample evidence that some octopuses and cuttlefish learn in a manner similar to learning in vertebrates. The common squid (Sepia officinalis), as well as the common octopus (Octopus vulgaris) And the day octopus (Octopuscyanea), can all form simple associations, such as learning which image on a screen predicts that food will appear.
Some cephalopods may be capable of more complex forms of learning, such as reverse learning which is learning to adapt behavior flexibly when different stimuli signal a reward. They may also inhibit impulsive responses. In a 2021 study in which common squid were given a choice between a less desirable but immediate snack of crab and a preferred treat of live shrimp after a delay, many of the squid found chose to wait for the shrimp.
A new frontier for animal welfare
Given what is known about their brain structures, sensory systems, and learning abilities, it appears that cephalopods are comparable in intelligence to vertebrates. Because many societies have animal welfare standards for mice, rats, chickens, and other vertebrates, logic would suggest that there is an equal case for regulations that enforce the humane treatment of cephalopods.
Such rules typically specify that when a species is kept in captivity, housing conditions must support the animal’s welfare and natural behavior. This view has led some US states to ban the law enclosed cages for egg-laying chickens And crates that are too narrow for pregnant sows to turn around.
Animal welfare regulations say little about invertebratesbut guidelines for the care and use of captive cephalopods have emerged over the past decade. In 2010, the European Union had to consider ethical issues the use of cephalopods for research. In 2015, AAALAC Internationalan international accreditation organization for ethical animal research, and the Federation of European Laboratory Animal Science Societies guidelines promoted for the care and use of cephalopods in research. The US National Institutes of Health is is currently considering similar guidelines.
The ‘alien’ minds of octopuses and their relatives are fascinating, not least because they provide a mirror through which we can think about more familiar forms of intelligence. Deciding which species deserves moral consideration requires selection criteria, such as number of neurons or learning ability, to inform those choices.
Once these criteria have been established, it may be useful to consider how they apply to the rodents, birds, and fish that fill more familiar roles in our lives.
This article was originally published on The Conversation by Rachel Blaser bee University of San Diego. Read the original article here.
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