1. Zebra Fish
Danio rerio

2. What is a zebra fish? Tropical freshwater fish Minnow family
Generation time is ~3-4 months
Adults ~ 4cm in length
Omnivorous
Eats primarily zooplankton, phytoplankton, insects and larvae

3. Why are zebra fish important?
The embryos are see-through
allows us to watch the changes in development
Adults breed rapidly
good supply of embryos for our research
Embryos develop quickly
4-5 days old the embryos become swimming larvae and start to catch their own food
Zebra Fish Development
Close homology to humans
More closely related to humans then models such as the worm and fruit fly, easier to use than mouse/rat

4. Development HPF=Hours Post Fertilization
UNFERTILIZED
FERTILIZED
HPF=Hours Post Fertilization
0 HPF HPF HPF HPF HPF HPF
16 HPF HPF HPF HPF HPF

5. Zebra in the classroom
Read through the zebra in the classroom article with a partner
What must be done in order for zebra fish to successfully breed?
Why are zebrafish embryos helpful for studying development?
What does hpf stand for?
What is it about zebra fish physiology that makes them good models to study in the lab?
Explain why biochemistry and genetics are important aspects to understand about the zebra fish.
Is it right to say that zebra fish are a “research tool”?
What information is most important to know for conducting an experiment with zebra fish?

6. Salt Solution (Test Salinity)
Concentration mg/Liter
Stock (40.0g/Liter) I.O. Solution
Distilled Water 60
.75 mL mL
120
1.5 mL
498.5 mL
240
3.0 mL
497.0 mL
480
6.0 mL
494.0 mL
1000
12.5 mL
487.5 mL
10,000
125 mL
375.0 mL
Must use 3 Concentrations of your choice

7. pH Solution (Test acidity)
Final volume of 500 mL
40 g/L Stock Solution I.O Solution
Distilled Water Part 1
Additions to adjust pH to final pH
pH 4.0
0.25 mL
150 mL
Add 0.1M HCl until pH 4.0
pH 7.0
Add either 0.1M HCl to lower or 1M NaHCO3to raise to a final pH 7.0
pH 10.0
Add 0.1M NaOH until pH 10
Must Use 3 Concentrations of your choice
ADD ACID TO WATER NEVER WATER TO ACID!!!

8. Ethanol Unstable…must make the day before use
[Final] in mM
[Stock] in mM
mL of Stock
mL of Embryo Media
Total volume
in mL
300
1000
100
350
450 33
333 30
Unstable…must make the day before use
Must use 3 Concentrations of your choice

9. Zebrafish Development - Zygote “The Bubble”
Zygote Period – 0 – 0.75 hpf
Fertilized Egg to develop with its first division of cells

10. Cleavage Period “The bubbles boil over”
Cleavage – 2.25 hpf
Cells begin to divide… still large enough to count

11. Blastula Period “The afro”
Blastula hpf
Cells multiply very rapidly at the top

12. Gastrula Period – “The Solar Eclipse”
Gastrula hpf
Outside of the cell begins to develop

13. Segmentation Period “ The six pack abs”
Segmentation – 24.0 hpf
Somites form around the midsection for segmentation.

14. Pharyngula Period “The fat belly”
Pharyngula hpf
Fish has large yolk sack present/ Body straightens

15. Hatching Period “The free fish”
Hatching hpf