Published on:

March 13, 2015

The Angelfish in the Room, Part II: Aquatic Communities

By Saryta Rodriguez

Some months ago, Chris Palmieri reached out to me to submit his amazing blog post about fish.  I promised him that I would eventually post a Part II, as I, too, have been disappointed by the Animal Liberation Movement’s consistent neglect of ocean life (other than whales and dolphins—the ones with whom most people already identify).  This week, the Daily Pitchfork also posted a poignant article about fish, telling me that perhaps these guys’ moment in the watery sunbeam has finally come.

I am happy to present to you the following excerpt from my book, Until Every Animal Is Free. This is from a section of Chapter Five: Where to Draw the Line? entitled “Nirvana Was Being Sarcastic: The Truth about Fish.”


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, schreckstoff, and mobbing behavior.

  Sergeant major damselfish.
Sergeant major damselfish.

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. While these activities do not require cooperation, 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.

  Sea urchins.
Sea urchins.

Schreckstoff 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.

  Whitebar gregory damselfish.
Whitebar gregory damselfish.

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 closing, it would appear that many fish take DxE's Fourth Organizing Principle to heart; they form communities in which they cooperate with and care about other members. They are not swimming carrots.  In Until Every Animal Is Free, I also explore the physiological aspects of fish and how they are capable of both suffering and experiencing fear.

It's time we stop ignoring the plight of ocean life and put the nonsense term "pescatarian" to bed. A fish is every bit as sentient and deserving of our care and compassion as a cow is.