The energy of life in zebrafish (lesson six of eight)

Author(s): Ben Engel, Arthur Millius, Lisa Monti and Helen Wong-Lew

Lesson Overview

Grade level(s):

Grade 3, Grade 4


Biology/Life Science


Energy in zebrafish

Big ideas(s):

Life needs energy to grow and develop.

Vocabulary words:

observe, record, label, predict, question, microscope, light source, objective, eyepiece, focus

What you need:

dissecting microscopes for each pair of students (SEP item #s E077-E088), power strips and extension cords sufficient to plug in all scopes, zebrafish of different ages, petri dishes




classroom where microscopes are set up and plugged in

Time needed:

1 hour

Author Name(s): 
Ben Engel, Arthur Millius, Lisa Monti and Helen Wong-Lew

We introduce the concept that life needs energy to grow. We explain a little about microscopy and then the students observe different stages of zebrafish development (except we do not tell them that it is a zebrafish). Then student predict what animal they are observing leading up to a big reveal.

Prerequisites for students: 


Learning goals/objectives for students: 

Learning Objectives 1) Life needs energy to grow. Energy can be stored in many forms including sunlight, food, fuel, and batteries. 2) Learn that atomic energy from the sun is converted into light energy, then into chemical energy by plants and algae, and finally into chemical energy for zebrafish (and other animals). 3) Animals are composed of organs, which are composed of tissues, which are composed of cells. 4) Learn the parts of a microscope. Language Goals 1) Introduce the terms observe, record, label, predict, and question. 2) Write descriptions, labels, and questions from their observations of zebrafish.

Getting ready: 

Collect fish and divide them among the petri dishes. Label each dish and setup of the microscopes.

Lesson Implementation / Outline


10’ Engage students by discussing microscopes. The class will try to predict what they are looking at.  Discuss the light source, focus knobs, eyepiece and objective on the microscope. Warn that the microscopes are extremely delicate and should be handled with caution.


10’ 0 day-old zebrafish: The kids move to the science room. They play with the knobs and the light source. Then the embryos are passed out to each pair. With help, they focus on zebrafish embryos. They draw what they see and the terms embryo, yolk, and cell are introduced. 10’ 1 day-old zebrafish: The 0 day-old fish are replaced with one day-old fish. The kids draw what they see. The kids are asked if they see more or less cells. They are also asked where they think the organism is getting energy. The terms division and development are introduced. 10’ 4 day-old zebrafish: The 1 day-old fish are replaced with the four day-old fish. Again, the kids draw what they see. The kids are asked now to predict what organism this embryo is. 10’ 7 day-old zebrafish: The 4 day-old fish are replaced with the seven day-old fish. Now, different tissues are visible. The concept that tissues are composed of cells is introduced. Introduce the idea that organs are composed of tissues. The kids are asked to make note of the blood, heart, eyes, tail, spine, and brain.

Checking for student understanding: 

After each life-cycle stage, review what students saw and label a picture of the embryo on the chalkboard.

Wrap-up / Closure: 

25’ Explain: Now reveal what the organism was – a zebrafish! Discuss how animals develop from single cells. Discuss cells, tissues, and organs and ask the kids to describe what they saw. Encourage  kids to uses the terms they learned when describing what they saw. For instance, “I observed the heart, which is composed of cells beating.” Finally, make reference to where the zebrafish get their energy and ultimately that all energy comes from the sun.

Extensions and Reflections

Extensions and connections: 

Students could do art project drawing their fish at different stages. The could write a story about the different stages of development.


We killed many zebrafish because the lamps on the microscopes shocked the embryos. Be sure to save enough fish for each class.

Energy of Zebrafish student wksht.doc20 KB

Standards - Grade 3

Physical Sciences: 
1. Energy and matter have multiple forms and can be changed from one form to another. As a basis for understanding this concept:
a. Students know energy comes from the Sun to Earth in the form of light.
Life Sciences: 
3. Adaptations in physical structure or behavior may improve an organism's chance for survival. As a basis for understanding this concept:
a. Students know plants and animals have structures that serve different functions in growth, survival, and reproduction.


another stage you can use

If you put new eggs at a colder temperature overnight (a cool part of the lab, for example) you can get "1 day old" fish that are closer to the 15-somite stage (between the new eggs and the standard "1 day" age). This makes another stage to look at where the fish start to look like animals, but aren't moving around yet.