Yes, Fish Feel Pain - and Yes, We Should Care

A recent article authored by Marc Bekoff Ph.D. published in Psychology Today has reaffirmed a truth I’ve known for a long time, but one which seems to be under constant contention in the scientific community: that fish feel pain*. Perhaps the foremost name in the field of fish sensory abilities is Victoria Braithwaite, author of Do Fish Feel Pain?* So it did not surprise me that Dr. Beckoff’s article begins with a quote directly from that work. This work was also a huge resource for me in composing my own chapter in Until Every Animal is Free, “Nirvana was Being Sarcastic: The Truth about Fish.”

One of the primary scientific explanations for which scores of scientists dismiss the possibility that fish can feel pain is that fish do not have the same pain receptors that we and other mammals do, which are called C-nociceptors* , and lack the neocortex* of which we humans are especially proud. Instead, fish have other types of nociceptors that are commonly described as having the ability to react to potentially damaging stimuli by exhibiting a “reflex withdrawal.” Studies in which fish were exposed to toxic stimuli and reacted by moving away or avoiding the source of the stimuli in the future are often summarized thus: The fish’s nociceptors caused them to reflexively avoid the toxin— without ever causing them the sensation of pain.

Reflex is defined primarily by its immediate and involuntary nature*. The distinction here is an important one, as it implies that fish, when avoiding stimuli, do not actually remember sensing any discomfort, nor do they cognitively know the source of it. We are expected to believe that their bodies function like machinery, moving towards what is good for them and away from what is bad for them without any real decision making process taking place.

My own research has confirmed, as Beckoff’s article does, that fish do in fact feel pain— which others sometimes describe as “discomfort.” The reluctance to use the word pain in relation to fish and instead use the milder term “discomfort” is reminiscent to me of the reluctance to use the word language when we talk about birds and whales, and instead employ phrases such as “vocal learning*.” These rhetorical nuances serve the purpose of preserving for us humans what we believe makes us superior to other life forms, while relegating whatever talents or abilities other creatures have to second-class status. We remain as a species ever reluctant to admit that anyone else can do what we do or feel what we feel.

Furthermore, humans have a tendency to empathize with and more strongly identify with those who we perceive to be “like us,” especially with regard to appearance. This tendency persists even within our own species. So while the sad eyes of a dog or cat can move us, the inscrutable eyes of a fish or a lobster do not. We must dig deeper within ourselves to find empathy for these creatures.

A 2004 study at the University of Guelph* in Ontario, Canada confirmed that beyond pain, fish are also capable of experiencing fear— and remembering it. In one part of the study, fish were exposed to a net, which was not used to harm them but which disrupted their routine, and were allowed to escape through a small door to an adjacent net-free tank. Then, they were shown a light just a few seconds before the net was plunged into their vicinity. This went on for about a week until eventually, the fish were able to recognize the light as a precursor to the net, and would flee to the adjacent tank before the net appeared.

Such activity cannot be dismissed as mere reflex. The first time the light appeared before the net, the fish did not flee; this response, therefore, was not immediate, but rather learned. The act was also voluntary, as the fish chose to avoid the stimuli rather than reflexively moving away from it. Were this response to the light involuntary, it would be identical every time the light was shone, whether the first or the fifteenth.

While fish lack a neocortex, they do in fact have nervous systems, and these complex nervous systems include neurotransmitters such as pain-relieving endorphins*. Why would anyone’s body naturally produce painkillers if that someone is incapable of experiencing pain? These endorphins serve no other practical purpose; they are not nutrient rich, don’t aid digestion, or anything of the sort. They strictly serve the function of relieving a sensation that people have argued for far too long fish simply never experience.

With such a preponderance of evidence that fish feel pain and fear at our fingertips, why does this remain such a bitter pill for folks to swallow? From a sociocultural perspective, I think it has to do with the way we perceive fish based on observation. Fish, to the naked eye, are “boring”— particularly in the settings in which most of us encounter live fish, which is in a small tank in someone’s living room, often alone but sometimes with three or four other fish, of different breeds. It’s hard for us to imagine that they can have any sort of rich inner life— that they can understand, say, prestige, companionship or cooperation.

In fact, many breeds of fish do have extensive social lives, though not much can be known of any “inner life” they might have due to the obvious communication barrier between us and them. Before we go any further, though, I would like to reaffirm my belief that even if they did not have such complex social lives, even if they were just mindless swimming robots who happen to experience pain and fear, but not much else, I still believe they deserve as much protection as any other sentient being. They have demonstrated, over and over again, their capacity for suffering, and we as humans should not seek to contribute to said suffering, no matter how simple or insignificant their lives may appear to us.

That said, I was very surprised to learn in researching fish for Until Every Animal is Free* that they are capable of both creating sophisticated social networks and cooperating with one another to achieve common goals. In closing, I would like to share with you a brief except from the book that highlights some of these impressive capabilities:

In a 2003 issue of the journal Fish and Fisheries, biologists Calum Brown, Kevin Laland, and Jens Krause asserted that there had been huge changes in science’s understanding of the psychological and mental abilities of fish at the turn of the century, and that fish were in fact highly intelligent—and highly social—creatures. The experts hail from the universities of Edinburgh, St. Andrews, and Leeds in Europe.

Now, fish are regarded as steeped in social intelligence, pursuing Machiavellian strategies of manipulation, punishment and reconciliation, exhibiting stable cultural traditions, and co-operating to inspect predators and catch food.
— Bshary and Wurth 2001; Bshary et al. 2002

What these biologists published was essentially a collection of essays (including the two quoted above) written in the Nineties and early 2000s regarding intelligence, socialization, and overall sentience in fish. They then proceeded to summarize important points about fish, using these studies to support their claims. Among the points for which this tremendous trio was able to find ample justification in recent research are:

That fish are able to identify individual shoal-mates and monitor the social prestige of others (Yes, apparently it is possible to be a prestigious fish.) (McGregor 1993; Bshari et al. 2002; Griffiths 2003);
That fish use tools (Bshary et al. 2002);
That fish build complex nests and bowers, similar to the bowerbird discussed in Chapter Two (Paxton and Eschmeyer 1998).

Dugatkin’s 1997 book, Cooperation Among Animals, explores various social behaviors observed in fish. Among these are cooperative foraging, intraspecific cleaning, shreckstoff, and mobbing behavior.

Cooperative foraging is typically the result of territorial defense, in fish as well as in many other species. A good example in the fish community is the relationship between sergeant major damselfish and those who prey upon them—members of the Labridae and Serranidae families, such as cleaner wrasses, sea basses, and groupers. Male sergeant major damselfish become hyper-aggressive when tending eggs, changing color from white to dark blue or indigo. They also defend their territory by nipping at fish and divers who invade their space. These activities do not require cooperation; however, foragers of damselfish eggs (such as sea basses) must cooperate in order to succeed against these formidable foes.

What this boils down to is that fish are not only capable of cooperating with one another—proof positive that their lives are not solitary but social—but also possess sufficient intelligence to discern when cooperation is necessary for success. Fish do not always cooperate in order to forage, but when confronted with a daunting obstacle between themselves and a desirable resource, they will team up for the sake of achieving a common goal. Humans behave much the same way; on a daily basis, we typically do things by ourselves, with minimal cooperation amongst our friends, relatives, and coworkers. When trying to achieve something too difficult for just one person, such as curing a disease or constructing a building, we form large teams—organizations, companies, committees, and so forth. An individual can “go vegan” without anyone else’s help, but it will take the strength of a community of animal liberationists to end speciesism once and for all.

Intraspecific cleaning refers to the practice of cleaning the bodies of others. Many mammals, for instance (such as monkeys), remove parasites from each other’s bodies. This behavior has been observed among carp, guppies, Panamic sergeant majors, bluegill sunfish, and other species of fish.

Shreckstoff was originally observed by Austrian ethologist Karl von Frisch in 1938, as a chemical alarm signal emitted by minnows. R.J.F. Smith defined this chemical signal in a 1992 study as “A response produced by an individual—the ‘sender’—reacting to a hazard that warns other animals—the ‘receivers’—that there is danger.” Since von Frisch’s original discovery, shreckstoff has been detected in other fish species besides the minnow, as well as among sea anemones, sea urchins, tadpoles, and even rats. Whether or not this is a social behavior is debatable, as it remains unclear whether fish actually choose to sound the alarm or it occurs naturally when a fish is under duress. Still, Smith argues that aside from chemical signals there exist certain auditory, tactile, and visual forms of shreckstoff that require intent to produce.

Mobbing behavior refers to the act of multiple potential prey coming together to attack or harass a potential predator. Dugatkin cites numerous studies in which this behavior has been observed among members of at least five groups of fish: bluegill, butterfly, threespot damsel, blue and gold damsel, and whitebar gregory (yet another subspecies of damselfish). A simple, individually minded creature would merely flee from a predator as quickly as possible once he or she has determined that a physical confrontation would be unwise; these guys stick together, teaming up against an individual bully. Their concern is not limited to their own safety but extends to that of their community.

In short, yes, fish feel pain. Not only do they feel pain, but they are also capable of experiencing fear, of learning, and of cooperation. Fish are killed in greater numbers* than any other nonhuman animal for the sake of human consumption. How much more evidence do we need of their consciousness before we start protecting them as we endeavor to protect pigs, cows, chickens, and other enslaved and exploited animals?

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