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Can Fish Tell Time?

Can Fish Tell Time?

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Science Fair Project Description

Organisms often follow a pattern or rhythm in their behavior. Birds migrate at a certain time of the year, while many animals sleep by day and are active by night. Many people can tell when lunch time has arrived without looking at a clock. Can fish do the same? This is the subject of this interesting zoology science fair project.
Complexity level:4
Time required:This science fair project for 5th graders, requires time to observe the behavior of the fish before starting the experiment. Additional time is also required to condition the fish to a new feeding schedule.
Safety concerns:


The biological clock, also known as the circadian rhythm, is an aspect of living organisms that regulates daily activities such as eating and sleeping. In plants, the biological clock tells the plant when to bloom or sprout. Can aquarium fish anticipate feeding time? What happens if the feeding time is changed? Can their biological clock be altered? Refer to the bibliography section for more information on biological clocks.

Scientific Terms

Biological Clock,


  • Aquarium fish (eg. gold fish)
  • Aquarium
  • Fish food
  • Timer


  1. To prepare for this cool science project, observe your fish daily to familiarize yourself with their swimming patterns. Does the fish tend to occupy certain parts of the tank more so than others?
  2. Create a feeding schedule whereby you feed your fish each day at the same time of the day.
  3. After a period of 1 week approximately, notice where the fish positions itself within the tank during feeding time.
  4. Continue for another 3 days, observing the fish's location at feeding time. Is the fish demonstrating a consistent pattern of behavior at feeding time?
  5. On day 4, change the feeding time. Observe the fish daily, both during the old feeding time and the new feeding time. How long does it take before the fish adjust to the new feeding time?


"What is your biological clock?" at the Essortment web site

Related videos

Hey there! Here are some awesome videos about this science project that we think you'll really like. They're not only super fun, but they'll also help you learn more about the science behind the project. So sit back, relax, and get ready to have some fun!!
Does your pet fish or other pets show anticipation for their scheduled feeding time, like this person's fish? What affects the fish's ability to tell time?
Discover recent research on a tide-dependent clock, which is different from the daylight-dependent circadian rhythm present in plants, fungi, bacteria, and animals.
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