Guppies from the pet store come in a wide variety of colors and fin shapes. In the Small Fish-Big Questions STEM Kit, students will compare pet store guppies to wild guppies from high and low predation environments in Trinidad. Through careful observation they will get a feel for how biological changes over time occur. These kits can only be borrowed and used in a school with the help of a graduate student from CSU’s Biology Department as they use live guppies.

Big Concepts include: 1) evolution,; 2) variability; 3) inheritance; 4) selection; and 5) time.

Scientific Inquiry Skills include:  1) observation of animal behavior; 2) data collection and analysis; 3) Punnett squares and statistics; and 4) use of science notebooks.

Small Fish-Big Questions STEM Kit Tutorials

  • Small Fish-Big Questions STEM Kit Use Instructions (complete teacher guide)
  • Small Fish-Big Questions STEM Kit Clean-Up & Repacking Instructions
  • Small Fish-Big Questions STEM Kit Material List

Small Fish-Big Questions STEM Kit Resources

CSU Resources

Other Useful Resources

Borrowing Small Fish-Big Questions STEM Kits

There is no charge to educators who wish to borrow borrow any of our STEM kits, but this kit may only be used by local teachers with the aid of a graduate student from the Biology Department at CSU who will bring the kits and guppies with them to the school. Return the loan application form to Laura Schoenfeld via email ( or fax (970-491-2005). We appreciate applications to be sent 2 weeks in advance to the desired use date.

A colorful guppy
A male guppy, less colorful.
Recording results of the Guppy Lab
Lab notebook with data