Guppy Fish Science Experiment

Amaze your kids with this Guppy Fish Science Experiment where you will breed guppies while learning about genetics, life cycles, and so much more! Includes a free printable observation book to help your students write down observations.

Science Project for Kids

This science project is a little involved, but teaches kids so many things about animals, life cycles, building an experiment, using the scientific method with kids, how genetics work in a simple way kids can understand, plus a big WOW factor. And other than time, all you need is an aquarium and a couple guppies from the pet store.

Whether you are a parent, teacher, or homeschooler – this is a really fun science project to try with your pre k, kindergarten, first grade, 2nd grade, 3rd grade, 4th grade, 5th grade, 6th grade, 7th grade, and 8th grade student.

Why we decided to Breed Guppies

In typical Beth fashion, one day I just decided – hey let’s breed guppies! My hubby knows by now that once I get an idea in my head it’s best to just go with it. So we set up a 10 galloon tank (we had spare in the garage) in the kitchen (because we’d walk by more often). We went out and bought 3 female and 1 male guppy and we waited. I made a Guppy Observation Book & our Kindergarten Guppy Breeding Science Experiment began.

Learning about Guppies in Homeschool Science

We read information about guppies online. We fed, cleaned, and cared for the guppies. We named and charted on the guppies. And we waited.

Guppy Science Fair Projects

Apparently guppies aren’t as hardy as they once were – the pet stores tell me it is from over breeding. Whatever it is we lost a couple females, bought a couple more, and bought a different male because ours seemed unable to perform his purpose.

Day 1+ We wrote in our note book about what we observed. We noted what they liked to eat, how they swam, how warm they liked the water, how much they poop (let me tell you it was a LOT), and came up with questions that we then looked up (such as how long do they live).
Day 31 days we had 2 babies. Not sure if the rest were eaten or what, but we had 2. (they kinda look like tadpoles)
Day 34 we only had 1 baby – the other one was eaten.
Day 42 we had 2 more babies. Again, not sure if the rest were eaten. We now had 3 babies

Day 47 – EUREKA! I noticed about 10 new babies in the tank. I quickly removed all the females (and put them in our 30 galloon community tank)except for the very large female who I put in a small goldfish style bowl to make sure she didn’t eat the babies. I took out the large fern (which really hadn’t served its purpose anyway) we had put in for the babies to hide in as there were no mommies in the tank to hide from & we could see them better. I went back to check on the Mommy & noticed there were babies in the bowl with her. The kids & I watched her give birth – so cool! After she had 20 she seemed to stop. The bowl was getting crowded so I emptied it back in the 10 galloon nursery tank. I pulled the Mommy back out so she didn’t eat the babies. I went about making lunch & taking care of Tinkerbell & she had 20 more!! Again, I emptied the babies into the nursery & removed the mother. The Mommy guppy didn’t have any more & I placed her in the community tank. After careful counting I discovered we had the original 3 babies plus 55 new babies!!
Day 85 – the 54 babies are growing a lot. They no longer look like miniature tadpoles. They look like miniature fish, about 3/4″ long. The fish are starting to show some color. The baby guppies eat a LOT – like all babies! They are finally eating normal food (no longer baby fry food) 4-5x a day.
Day 114 – The guppy fish breeding babies are full grown! They are 1 1/4” long & have all the color they are going to get. I decided our observations should be done to get the fish to a better home.

Breeding Guppies

Not that we don’t enjoy watching them…. but 58 fish in a 10 galloon aquarium isn’t really the best home. It means I have to change the water every 5 days or so! Since it is really hard to count fish when they are one big mob in the small tank, we separated them into bowls – 5 to be exact. This was also a great chance to practice counting by 10s! There were 10 fish in each of the 5 bowls with 8 fish remaining in the aquarium.

Graphing Guppies

Then we counted how many fish of each color there were & graphed them 3 ways:

Graphing Guppies in Color on Graph Paper
Graphing Guppies with cuisenaire rods
Visualizing Guppy Babies on a pie graph

baby guppy pie graph - conceptualizing a different way

Cuisenaire Rods - conceptualizing numbers

I thought it was neat to see his little brain process the information. He couldn’t conceptualize what the numbers mean, but when we graphed the colors he looked at me with amazement and said – there are WAY more red than any other color! It was pretty cool to see him “get it”

It was a really fun experiment and we learned a lot! Students from preschoolers, kindergartners, grade 1, grade 2, grade 3, grade 4, grade 5, grade 6, grade 7, and grade 8 will love trying this science experiment. I’d really like to try egg layers next…..

Fun Summer Activities

Looking for more outdoor activities for kids and things to do in the summer? Your toddler, preschool, pre k, kindergarten, and elementary age kids will love these fun ideas to keep them busy all summer long: