1. 
Small tropical fish native to southeast Asia

2. 
One couple produces hundreds of offspring per week

3. 
Eggs are fertilized and develop outside the body

4. 
Embryos are transparent and can be viewed and manipulated at all stages

5. 
The larvae hatch two days after fertilization; five days later all the vital organs are developed; in two to three months the young fish are capable of breeding new offspring

6. 
As a vertebrate, it has the same major organs and tissues as humans

7. 
The use of zebrafish as a model organism began in the 1960s

8. 
The complete genome sequence was published in 2013

9.
Genome contains 1,505,581,940 base pairs and 26,247 protein-coding genes

10. 
It has a similar genetic structure to humans; around 70% of human genes have at least one similar gene in the zebrafish

11. 
The second most used animal in medical research, replacing the use of rats in many cases

12. 
84% of genes known to be associated with human disease have a zebrafish counterpart

13.
They are amenable to both forward and reverse genetic approaches, with a research toolset regularly updated

14. 
Once a gene has been identified as linked to a specific disease, zebrafish can be genetically modified to create an animal model of the disease, which scientists can use to test new treatments

15. 
They are highly regenerative, able to regrow amputated fins, as well as a lesioned brain, retina, spinal cord, heart, and other tissues

16. 
If part of a zebrafish’s heart is removed it can grow back in a matter of weeks. Specific factors involved in this process will help us to develop ways of repairing the heart in humans with heart failure or who have suffered heart attacks