Drunk Fish Convince Sober Ones to Follow Them Around

By Elizabeth Preston | May 19, 2014 8:53 am


It’s a good thing fish can’t operate a vehicle. Not only do drunk zebrafish swim extra fast, but they somehow get all the sober fish to follow them. Essentially, a drunk fish becomes the designated driver for the whole group.

Although a fish is only marginally like a human, fish can be convenient subjects for scientists who want to study the effects of alcohol. That’s because to get a fish tipsy, you don’t have to force it to drink anything. You only have to put a small concentration of alcohol into its tank.* Maurizio Porfiri, an associate professor at the New York University Polytechnic Institute of Engineering, used this technique to show last year that drunk zebrafish don’t fear robotic predators.

For his latest study of intoxicated fish, Porfiri and his coauthors had their subjects swim in three different alcohol concentrations: 0.25%, 0.5%, and 1%. The highest concentration translates to about a 0.1% blood alcohol content in the fish, Porfiri says—above the legal limit of .08% for people in the United States.

Earlier studies had found that a moderate dose of alcohol makes fish more active, while a higher dose slows them down. But for this study, Porfiri wanted to see how an alcohol-exposed fish would behave when it was surrounded by sober ones.

After letting each zebrafish soak for a while in a beaker of water and ethanol, he dropped it into a tank with four sober zebrafish and watched them interact for five minutes. A camera recorded the group from above so that the scientists could measure the fishes’ movements using a tracking algorithm they’d recently developed.

Alcohol-exposed fish swam faster in a group than they did alone. This might be because moderate intoxication makes them hyperactive, as earlier studies found; they may overreact to the stimulus of seeing other fish nearby. Moderate amounts of alcohol are also known to lower fishes’ inhibitions, making zebrafish more aggressive and less afraid of unfamiliar things (or predators).

Meanwhile, the four sober fish didn’t ignore their intoxicated peer as it zipped around the tank: they followed it.

There are a couple of possible explanations for this, Porfiri says. Maybe something about the drunk fish’s one-on-one interactions with the other fish made the group as a whole move in the same direction. Or maybe the sober fish looked at their non-sober tankmate and saw a leader. “It is likely,” Porfiri says, that the drunk fish’s uninhibited behavior “is perceived as a boldness trait, thus imparting a high social status.” As they followed the drunk fish, the sober ones also sped up to keep pace, swimming roughly a third faster than they would have otherwise.

The very drunkest zebrafish, though, lost their leader status. Fish that had been exposed to the highest alcohol concentration began to lag behind the rest of the group, following instead of steering. Since higher alcohol doses have “sedative effects,” Porfiri says, the drunkest fish slow down and start to display “sluggishness in response to the rest of the group.”

Porfiri isn’t ready to conclude that being buzzed turns humans into better leaders. It’s true that one reason to study alcohol-imbibing zebrafish is to make comparisons to human behavior. But “these similarities exist at a very basic level,” he stresses. “It would take many more studies to draw direct parallels” between ethanol-dunked zebrafish and soused people. Perhaps by then, the fish will have learned how to designate a driver.

*Please don’t kill your fish trying to do this at home. I don’t want little Betta-Zoid’s blood on my hands.

Image: zebrafish by Tohru Murakami (via Flickr)

Ladu F, Butail S, Macrí S, & Porfiri M (2014). Sociality Modulates the Effects of Ethanol in Zebra Fish. Alcoholism, clinical and experimental research PMID: 24819037

  • Joan_Savage

    Do the researchers know if sober zebrafish might follow any zebrafish that is more active?

    • http://blogs.discovermagazine.com Longmire

      The research would definitely justify the drug use of many a politician.

  • http://www.worthynews.com/ Joe DeCaro

    Since fish are only “marginally” like humans, who funds this nonsense?

    • Doug

      I’m thinking…. New York University Polytechnic Institute of Engineering, just like the article references.

      • http://www.worthynews.com/ Joe DeCaro

        NYU is doing the research, if you could call getting fish drunk “research”.

    • Jack Brewer

      You don’t. Why should you care?

      • http://www.worthynews.com/ Joe DeCaro

        Frankly after two years I no longer do.
        So why do you?

        • Jack Brewer

          If you have more than two brain cells, try answering your own stupid question.

          • http://www.worthynews.com/ Joe DeCaro

            Assuming you have more brain cells than a fish, if Polytechnic’s “research” was taxpayer funded, you would realize that we all paid for getting fish drunk.

          • Jack Brewer

            Send us you address. We will refund your .00001 cent tax amount that went to the drunk fish research, presuming you paid any taxes. Then, we will double the bill for any benefits directly, or indirectly derived from your narrow minded scope about research.

          • http://www.worthynews.com/ Joe DeCaro

            You can send the entire cost of your so-called research on intoxicated fish back to the U.S. Treasury.
            Hopefully the bill for the shrimp on the treadmill experiment will follow suit.

          • Jack Brewer

            “Hopefully the bill for the shrimp on the treadmill experiment will follow suit.”

            The “bill” for the well deserved and useful scientific inquiry into food safety is beyond the scope of republican idiot politicians who have neither the mental space to understand, or genuine concern for constituents, and who are a long way from scientific principles, to know what the three marine biologists’ work means.

            Besides, the cost of the treadmill is $50. You should change your political affiliation, or go to school so that your criticisms would be elevated to INFORMED critical inquiry.

          • http://www.worthynews.com/ Joe DeCaro

            Food safety, as in safe exercises for shrimp prior to its becoming food?

          • Shane Harris

            I love this thread. Reviving another 2 years later. Where is Jack and Joe now? Still harbouring the same contempt for eachother? Find out in another two years for the next installment!

          • https://sites.google.com/site/joedecaro/home Joe DeCaro

            My contempt is for any unnecessary spending that has contributed to today’s $20 trillion debt.

            And that contempt includes the ludicrous concept of intoxicating zebrafish, which are “only marginally like a human” yet were still being studied to “make comparisons to human behavior.”

          • Mark Spears

            Here’s the thing, Joe. (Sorry for reviving a zombie thread yet again.) You don’t seem to understand how federal research grants work. The scientists can’t just go to Congress and say “We need $1,000 to study drunk zebrafish” and expect a free handout.

            The government decides what percentage of the budget to allocate to research projects at the beginning of the fiscal year. This year, it was 0.78% of the budget. Then, universities and other research institutes send a list of the things they WANT to study (drunk zebrafish isn’t on there, but I’ll get to that in a minute) and an estimate of how much it’ll cost. Then a committee decides how to divide up the money.

            Here’s where the drunk zebrafish come in. If you don’t use ALL of your federal research money for this year, you won’t get as much next year. The committee that allocates the research grants will assume that you were deliberately inflating your estimates. So if you have $50 left in your budget, and you don’t spend it, you could lose tens of thousands of dollars next year.

            This is why we end up with silly research projects to inform us that the most dangerous room in the house is the bathroom. No, really? That tiny room that’s usually slippery with humidity and has lots of sharp corners that you can hurt yourself on? That’s the most dangerous room in the house? You don’t say!

            Or, in this case, silly research to study the behavior of drunk zebrafish, just to keep their research funding from being reduced. At least, I’m assuming that’s why they decided to study drunk zebrafish. If there’s some practical application for this research, I fail to see it.

            Anyway, I just wanted to explain where these silly research projects come from. It doesn’t affect the deficit, because the money has already been allocated at the start of the year when the federal budget is drawn up. It’s essentially “makework” to ensure they spend their entire budget.

          • https://sites.google.com/site/joedecaro/home Joe DeCaro

            I would have thought that researchers who return unused funds would be rewarded by the feds for future consideration while punishing labs that fund ridiculous research just to zero balance their budget.

          • Mark Spears

            You’d think so (and I used to think so too), but that’s not the case. I’ve got a friend who works for a medical university. About three years ago, I said something to him about ridiculous research, and he was the one who corrected me and explained how it works.

            Anyway, the point is that the amount of federal money earmarked for research is less than one percent of the budget. And the ridiculous research doesn’t increase the deficit because that money’s *already* been specifically allocated for research. If it wasn’t given to [X], it’d be given to [Y]. One way or the other, that money’s already been set aside.

            I’m not very concerned about ridiculous research because it is such a tiny fraction of the budget. What I am MORE concerned about is pork barrel projects. For example, the Navy requested ONE LCS (Littoral Combat Ship), but they’re getting THREE. Why? Because two Senators on the appropriations committee wanted to save jobs in their state, so they allocated money for two more ships just to keep the shipyards working. Those two extra ships (including the modules to make them combat-ready) are going to cost around $1.2 billion. Compared to that, a research project that probably only cost a few hundred dollars is pretty insignificant.

          • https://sites.google.com/site/joedecaro/home Joe DeCaro

            Military overspending is probably the most egregious waste of taxpayer dollars. But though there are more significant wastes of cash, ridiculous research still sets a bad precedent by making a joke out of scientific spending.

            And then there’s the Climate Change con, formerly called Global Warming. It’s a redistribution of wealth scheme that can costs countries billions to maintain a low “carbon footprint,” whatever that is.

          • Mark Spears

            All I’m going to say is that climate change is not a con. The U.S. military is very aware of it, and very concerned about it. The Navy has been building higher piers at bases on the east coast, and has been debating the best ways to move entire bases if necessary. They’re especially concerned about Guam because of how important it is to U.S. naval strategy.

            Five of the Solomons Islands have already disappeared. The Maldives will be uninhabitable by 2100. If nothing is done, most of Florida south of the panhandle will be underwater by 2200. Salt water has already moved 6 miles inland in Broward County and is likely to continue to creep westward. (Florida is already spending $500 million to research ways to combat rising sea level.) Hurricanes are, in general, getting more powerful because they get their energy from warm water, and the average sea temperature has been rising.

            I’m not going to waste your time or mine with a giant wall of text, but the facts are there. You just have to be willing to dig for them, and not take what the President says at face value. Even FEMA has already declared that they won’t give out money to states that don’t plan for climate change. So while Trump can deny it until he’s blue in the face (I’m not sure if that’s an improvement over orange… seriously, he either needs to stop eating so many carrots, or cut back on the artificial tanner), his own administration is well aware of it.

          • https://sites.google.com/site/joedecaro/home Joe DeCaro

            One word: Climategate.

            From: Phil Jones. To: Many. Nov 16, 1999
            “I’ve just completed Mike’s Nature [the science journal] trick of adding in the real temps to each series for the last 20 years (ie, from 1981 onwards) and from 1961 for Keith’s to hide the decline.”

            “Critics cite this as evidence that data was manipulated to mask the fact that global temperatures are falling. Prof Jones claims the meaning of “trick” has been misinterpreted….”

            Trick, con, whatever.


          • Mark Spears

            You really shouldn’t rely on an email written 20 years ago, when the science supporting global warming was much less solid than it is today.

            Those who oppose taking action to curb climate change have engaged in a misinformation campaign to deny the existence of the expert consensus. Less than 16% of Americans are aware that the scientific consensus among experts is IN EXCESS OF 90%. Is there still some debate among scientists? Sure, and there probably always will be, until it becomes so obvious that they can’t keep burying their heads in the sand anymore.

            The government (and oil and gas companies) have been caught paying off scientists to downplay the results of their research. Let me reiterate: There are documents FROM EXXON’S OWN SCIENTISTS that proves that the company KNEW about the effect of global warming, and fossil fuel’s role in it, for several decades. And deliberately suppressed it in the interest of More Money.

          • https://sites.google.com/site/joedecaro/home Joe DeCaro

            From: Phil Jones. To: Many. Nov 16, 1999
            “I’ve just completed Mike’s Nature [the science journal] trick of adding in the real temps to each series for the last 20 years (ie, from 1981 onwards) and from 1961 for Keith’s to hide the decline” is not about climate change, but describes outright deception.

  • http://goodbyemag.com Steve Miller

    This is the kind of headline I wish I could put on my stories

  • A Woman

    Alcohol is a poison to both fish and humans. I hope you don’t expose these fish to other toxins just to speculate about their reactions. Poison=bad

  • Xiang Ji

    Such a farfetched nonsense with an awkward theory. How can you know what the fish are “thinking”? Maybe some more followed the fish because it had a eerie smell, or simply random results. I certainly don’t think we humans tend to follow a drunkard all the day, at least when it comes to important and serious matters. A terribly usupported and misguiding claim.

    • http://blogs.discovermagazine.com Longmire

      People tend to follow courageous individuals, alcohol is known as liquid courage. Drunk people rarely respect the authority of or submit to another hence others follow. Psychology isn’t ideal.

  • Robert Heinz

    2 things –
    1. Fine print is for things that you’d rather people not read.
    2. I feel like it was a bit of a leap to say that the fish saw him as a leader who had “higher social status”. Why wouldn’t you first look back at a natural response that a fish may have. Seeing another fish swimming fast and swimming after it is probably a survival trait more than anything else. With a fish’s limited vision, if you see one of your own running in a certain direction, your instinct is gonna be that he is running from something and that you should follow.



Like the wily and many-armed cephalopod, Inkfish reaches into the far corners of science news and brings you back surprises (and the occasional sea creature). The ink is virtual but the research is real.

About Elizabeth Preston

Elizabeth Preston is a science writer whose articles have appeared in publications including Slate, Nautilus, and National Geographic. She's also the former editor of the children's science magazine Muse, where she still writes in the voice of a know-it-all bovine. She lives in Massachusetts. Read more and see her other writing here.


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