Octopuses And Their Relatives Are A New Animal Welfare Frontier
California and Washington approved bans on octopus farming this year. 贬补飞补颈驶颈 has considered similar action.
We named him Squirt 鈥 not because he was the smallest of the 16 cuttlefish in the pool, but because anyone with the audacity to scoop him into a separate tank to study him was likely to get soaked. Squirt had notoriously accurate aim.
As , I鈥檓 used to assaults from my experimental subjects. I鈥檝e been stung by bees, pinched by crayfish and battered by indignant pigeons. But, somehow, with Squirt it felt different. As he eyed us with , he seemed clearly to be plotting against us.
Of course, I鈥檓 being anthropomorphic. Science does not yet have the tools to confirm whether cuttlefish have emotional states, or whether they are capable of conscious experience, much less sinister plots. But there鈥檚 undeniably something special about cephalopods 鈥 the class of ocean-dwelling invertebrates that includes .
As researchers learn more about cehpalopods鈥 cognitive skills, there are calls to treat them in ways better aligned with their level of intelligence. California and Washington state both .
Hawaii is , and a ban on has been introduced in Congress. A planned octopus farm in Spain鈥檚 Canary Islands is attracting and .
Critics offer , including possible releases of waste, antibiotics or pathogens from aquaculture facilities. But as a psychologist, I see intelligence as the most intriguing part of the equation. Just how smart are cephalopods, really? After all, it鈥檚 legal to farm chickens and cows. Is an octopus smarter than, say, a turkey?
A Big, Diverse Group
Cephalopods are a broad class of mollusks that includes 鈥 cuttlefish, octopus and squid 鈥 as well as . Coleoids range in size from (Idiosepius) to the largest living invertebrates, the (Architeuthis) and (Mesonychoteuthis) which can grow to over 40 feet in length and weigh over 1,000 pounds.
Some of these species live alone in the nearly featureless darkness of the deep ocean; others live socially on active, sunny coral reefs. Many are skilled hunters, but some feed passively on floating debris. Because of this enormous diversity, the size and complexity of cephalopod brains and behaviors also varies tremendously.
Almost everything that鈥檚 known about cephalopod cognition comes from intensive study of just a few species. When considering the welfare of a designated species of captive octopus, it鈥檚 important to be careful about using data collected from a distant evolutionary relative. Marine the distributed structure of cephalopod brains and how they use that neural power.
Can We Even Measure Alien Intelligence?
Intelligence is fiendishly hard to define and measure, even in humans. The challenge grows exponentially in studying animals with sensory, motivational and problem-solving skills that differ profoundly from ours.
Historically, researchers have tended to focus on whether animals think like humans, ignoring the abilities that animals may have that humans lack. To avoid this problem, scientists have tried to find more objective measures of cognitive abilities.
One option is a relative measure of . The best-studied species of octopus, Octopus vulgaris, ; that鈥檚 relatively large for its small body size and similar to a starling, rabbit or turkey.
More accurate measures may include the size, neuron count or surface area of specific brain structures thought to be important for learning. While this is useful in mammals, the nervous system of an octopus is built completely differently.
Over half of the neurons in Octopus vulgaris, about 300 million, are not in the brain at all, but distributed in 鈥. Within the central brain, most of the remaining neurons are dedicated to visual processing, leaving less than a quarter of its neurons for other processes such as learning and memory.
In other species of octopus, the general structure is similar, but complexity varies. Wrinkles and folds in the brain increase its surface area and may enhance neural connections and communication. Some species of octopus, notably those living in reef habitats, , suggesting that these species may possess a higher degree of intelligence.
Holding Out For A Better Snack
Because brain structure is not a foolproof measure of intelligence, behavioral tests may provide better evidence. One of the highly complex behaviors that many cephalopods show is visual camouflage. They can open and close tiny sacs just below their skin that contain colored pigments and reflectors, revealing specific colors. Octopus vulgaris has up to 150,000 chromatophores, or pigment sacs, in a single square inch of skin.
Like many cephalopods, the common cuttlefish (Sepia officinalis) is thought to be colorblind. But it can use its excellent vision to produce across its body as camouflage. The , Sepia apama, uses its chromatophores to communicate, creating patterns that attract mates and warn off aggressors. This ability can also come in handy for hunting; that blend into the background or even lure their prey.
The hallmark of intelligent behavior, however, is learning and memory 鈥 and there is plenty of evidence that some octopuses and cuttlefish learn in a way that is comparable to learning in vertebrates. The (Sepia officinalis), as well as the (Octopus vulgaris) and (Octopus cyanea), 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 complicated forms of learning, such as 鈥 learning to flexibly adjust behavior when different stimuli signal reward. They may also be able to inhibit impulsive responses. In a 2021 study that gave common cuttlefish a choice between a less desirable but immediate snack of crab and a preferred treat of live shrimp after a delay, many of the cuttlefish . Cuttlefish adapted from the Stanford 鈥渕arshmallow test,鈥 which was designed to see whether children could practice delayed gratification.
A New Frontier For Animal Welfare
Considering what鈥檚 known about their brain structures, sensory systems and learning capacity, it appears that cephalopods as a group may be similar in intelligence to vertebrates as a group. Since many societies have animal welfare standards for mice, rats, chickens and other vertebrates, logic would suggest that there鈥檚 an equal case for regulations enforcing humane treatment of cephalopods.
Such rules generally specify that when a species is held in captivity, its housing conditions should support the animal鈥檚 welfare and natural behavior. This view has led some U.S. states to outlaw and .
Animal welfare regulations , but guidelines for the care and use of captive cephalopods have started to appear over the past decade. In 2010, the European Union required considering ethical issues when . And in 2015, , an international accreditation organization for ethical animal research, and promoted guidelines for the . The U.S. National Institutes of Health is.
The 鈥渁lien鈥 minds of octopuses and their relatives are fascinating, not the least because they provide a mirror through which we can reflect on more familiar forms of intelligence. Deciding which species deserve moral consideration requires selecting criteria, such as neuron count or learning capacity, to inform those choices.
Once these criteria are set, it may be well to also consider how they apply to the rodents, birds and fish that occupy more familiar roles in our lives.
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