Fish Experiment

Over the past few days I have been running my trials for experiment that was oh so controversial last time I blogged about it. I have been placing two groups of six fish into two solutions containing 0.5% ethanol and 0.25% ethanol. I place them into the solutions for a few hours then compare grouping behaviors. I compare grouping using a computer program to take a picture of the group every minute for 30 minutes. I then use a different computer program to measure the area of the group. The fish spend approximately 10 hrs. in the ethanol solution. After that I put them in a tank with just water, the “sober tank,” overnight and start all over again in the morning.

I am hoping to observe the development of alcoholic tolerance over the course of this experiment. Other studies that I have found doing this sort of thing exposed the fish to alcohol 24/7. I am hoping to observe similar results, but limiting the exposure time to the alcohol. Whether this will happen or not I do not know. When I crunch all of the numbers next week for my report I will find out how this experiment turned out.


  1. caynazzo says

    I once volunteered in a study similar to the zebrafish one you’re conducting. I was given ethanol intravenously and the effect on sensory perception was nearly immediate. Since the fish are absorbing it through their gills, I’m guessing they’ll feel the same…but I find it hard to believe they’ll be as dehydrated as I was the next day.

  2. Mooser says

    After the experiment proving alcohol is no good for you, an experiment showing the perils of premarital sex to zebra-fish is next. Thus the humble zebra-fish shows us the value of abstinence and temperance.

  3. Arnaud says

    Unless they start writing like Verlaine or Bukowski, or painting like Lautrec or Van Gogh, in which case we’ll all have to take a dive in the tank!

  4. Mike Fox says

    What would you expect tolerance from? More enzymes in the liver? Adapting to the dehydrating state of drunkenness? Their cerebellum getting used to the disruptive effects of alcohol? The dopaminergic reward pathways giving less reward for being put into this tank? Some sort of gill adaptation to resist alcohol?

    I’m not sure I understand what any of these would have to do with their grouping habits, unless fish that feel reward tend to group. Why would they do that?

  5. says

    How about improved navigation or co-ordination under the influence? Or showing the effects more quickly after repeated exposure? Are they big enough for a liver analysis?

  6. Bee says

    Not dissing your experiment, but I once knew a scientific minded four year old who poured a bottle of black ink into an aquarium. She wanted to know if fish could swim in the dark.

    Fatal flaw in experiment: she couldn’t see ’em.

  7. Mooser says

    Unless they start writing like Verlaine or Bukowski, or painting like Lautrec or Van Gogh, in which case we’ll all have to take a dive in the tank!

    Posted by: Arnaud

    In 40 years of aquarium keeping, I have only known one fish who even the slightest pretension to literary originalty. Most of the stuff is embarassing derivative, especially if the tank is in the same room as the TV.
    I don’t see ethanol or even seminars improving this situation, but you know what writers are.

  8. Airor says

    The observed behavior is grouping, and you’re moving them from tank to tank? Don’t you think the learned fear of the 2x a day transfer will have a monumentally bigger effect on grouping than the alcohol? Wont the transfers and the constant shocks to their system kill them faster than the alcohol?

    Also, how are you keeping the ethanol solutions constant? Won’t the ethanol evaporate out of the tank or be absorbed into the plastic of the aerator? Are you sure they’re getting ‘tolerant’ or simply processing what was in there into something else over time?

    What is your null hypothesis? What would be the result that says you were wrong? If you expect a difference in group volume between the experiment and control, don’t you need at least two controls to make sure they don’t differ either? In fact you’d need more than two to know the expected standard deviation of volumes over time and with the treatment of the fish held at a constant. Your only variable is supposed to be the alcohol, but you’re adding all these other factors and you’re expecting exactly what you’re bound to get: a difference of some unspecified magnitude.

    Add to this the fact that your experiment, to be valid, would have to be double blind. You shouldn’t know as you handle the fish which group had what percent of ethanol because you’re going to treat them differently when you handle them. Some fish are going to be harder to transfer, some are going to have distinguishing marks, even if it’s unconscious the fish will be treated differently. Since group volume will be largely (and probably solely) depend on how afraid the fish are, even unconsciously treating them differently will skew your results.