Feb 2003 TFH Column - Fish Social Behavior
Feb 2003 TFH Column
Fish Social Behavior

Richard J. Sexton

Why is it we do what we do? What explains our behavior? There is a reason we (or our fish) do everything; without that reason, it would not have happened. Is it all really rooted in the goals self-preservation and reproduction? Why do fish act as they do? Do we bear any behavior as humans that can be traced back to long before were were bipedal and air breathing? Is singing in the shower putting us in touch with our inner fish? In combative encounters which is more important, size or winning experience? How can I grow more eels? Dylan was wrong on this count, the answer it not blowin' in the wind, it's at the urls on this page. I've bypassed the "why cichlids act like cosy married people when they're breeding" stuff hoping that other contributors to this issue will have covered that, and instead presumed the thesis: "poeple act like fish". To turn things around a bit, the next time you're thinking to yourself "it's really neat the way these fish act like people sometimes" ask yourself the question instead "we act the same, which came first?" then go look for piscine behavior in the human condition and ponder again the evolutionary line.

I scored a direct hit in the "singing in the shower" article below: rock and roll stimulates a part of the brain thought to be used only by fish. Aha, gotcha.

Do bettas learn about potential opponents by watching them fight with other males? Somewhere over in Norway somebody got paid to play with Bettas for a good long time then write it up with all sorts of heavy statistics. Man, that sure beats working. Seriously, this is a fascinating read with some rather clever insights into animal behavior that just happened to use Bettas as subjects.

Another formal paper, this time some folks messing around with green swords trying to figure out at what point being bigger helps win battles if you've a history of losing them. Apparently it's true: size isn't everything and experience matters.

"Studies on trout fry led Brown (1957) to conclude that the presence of larger fish has a suppressive effect on smaller companions, through the direct impact of aggression on growth rather than through competition for food." is the opening quote from this page that has the title of "Improve your eel farm". If you have an eel farm, this is your guy, and I've no doubt you'll have bigger happier eels in no time and more of them. The rest of you without eel farms (and I sadly admit that includes me, not that I haven't thought about it seriously from time to time mind you) can glean some useful information here about why it might be a good idea to sort fish for size if you're raising a batch of fry and a bunch of other interesting ideas. This article isn't as rigorous as the previous two, which does not mean it's wrong and maybe it's just me but I don't see a lot of empirical evidence to back some of the assertions up. At any rate it's still an interesting read, eels or Apistogrammas, at the end of the day fish is fish and some of this may be relevant to the average aquarist.

Speaking of Apistogramma, have a look ar George Barlow's site. A professor emeritus University of California, Berkeley whose current area of work involves Julidochromis. Professor Barlows credentials are very impressive but struck me is this one line at the bottom of he "for aquarists" page: "I continue to work up data from old experiments and to report the findings in the scientific literature. I also pursue literature research, primarily on the biological roots of war." The biological roots of war. Now if that doesn't send shivers down your spine, what will?

Odd domain name, but a handy page to bookmark; there's some good articles linked from this page. The one on the top 20 fish imported into the US, while it has no eye-openers, it's interesting to see just what the pecking order is. Hint: guppies win. There's a page describing what US states it is illegal to import a Piranha into. There is an article about how we might have got our love of loud rock and roll from fish a very long evolutionary time ago. These two quotes tell all: "When music is played loudly it seems to trigger, through the sacculus, the same part of the brain that produces powerful sensations associated with activities such as sex, hunger and bungee jumping" and "The distribution of frequencies that are typical in rock concerts and at dance clubs almost seem designed to stimulate the sacculus," Mr. Todd said. "They are absolutely smack bang in this range of sensitivity." While this is all well and good if this months column was about fish-trivia, it's not it's about behavior and the article here "why fish shoal" which explains the differences between schools and shoals and why fish do that. Bottom line, and pretty sage advice if you ask me: "Try not to get killed. Reproduce". To quote Jack Nicholson's character in the "The Shining": "words of wisdom Lloyd, words of wisdom..."

Here's another one that makes you go "hmmmm"; it's not really about fish social behavior, it's about the idea that we can make inferences if postmodern man's behavior by studying fish in an aquarium; both will only ever live in a "man made" not a "natural" environment. There's a nice little jab in the last line of this page too.

Another formal paper, this one is out of Europe, and talks about cooperative breeding; while it happens a lot in birds and mammals, only 8 fish species do it. This paper looks at some of the advantages and issues regarding this

In my teens, on that day when I first picked up a copy of TFH in the local pet store, knowing what I knew then (nothing), I could only shake my head at some of the stuff in there, it just went right over my head. It's probably a good compromise if half your audience thinks it's "too light" while the other half thinks it's "too advanced". Ok, so here's a good counterpoint to the serious behavioral articles shown here from scholarly journals, this is a good old fashioned web page (sic) about Tropheus species - keeping and breeding, with a good description of the unusual reproductive and social behavior these fish have evolved to. Great pictures too.

Now this one's a little different. We don't often find things of relevance to aquarists in the New York Times and this is tangential at best being about astronomers, and not aquarists. But there's a catch, and a lesson here:

" Mr. Puckett sits down at a computer in his home in the foothills of Fort Mountain in Georgia and plots the targets for three motorized telescopes in the observatory he designed and built outside. With Mr. Puckett back in the comfort of his home, the computer takes over, pointing the telescopes at the targets, one after the other, and telling digital cameras attached to them to take pictures.

The nightly harvest is about 1,000 images, which Mr. Puckett then shares with a half-dozen other amateur astronomers over the Internet. Together, they analyze the pictures for previously undiscovered supernovas, the remains of collapsed stars.

His group has discovered 58 supernovas.

While most amateur astronomers use computers to enhance a hobby, the advances in technology are also blurring the distinctions between professionals and sophisticated amateurs like Mr. Puckett."

It's those advances in technology that are meaningful, for many of the papers you'll find on the study of fish social behavior involve repetitive observation of a large number of events and a lot of hairy statistics that the observations are interpreted with. If you look at the trend in decentralization in computing there's really no reason why "amateurs" cannot perform the same kinds of experiments that professional ichthyologists can just by splitting up the workload and pooling information on the Internet. SETI@Home ( is a good example of something like this.

What if it was YOUR son that got pregnant? Say "pregnant males" and of course seahorses come to mind. This article from Science New Online touches on a number of interesting points of fish social behavior with a theme common to other articles about fish behavior and that is drawing parallels in human behavior even if just conjecture? This article suggests Arnold Schwarzenegger... might be a better mother than a father.