Zebrafish (Danio rerio) is a tropical fresh water fish, which has become the most commonly used and favourite vertebrate model in biomedical research in recent years. Ease of maintenance, optical clarity and rapid development of the embryos made zebrafish a favourite model for developmental biologists, but recent developments in transgenesis and other genetic manipulation tools make it a ubiquitous animal model in a wide range of fields from cardiovascular disease to visual disorders . The zebrafish genome consists of 25 chromosomes with a total size of 1.412 gigabase. Zv9 assembly shows zebrafish have 26,206 protein-coding genes, the highest gene number of any sequenced vertebrate species. The zebrafish genome has its own features, including the highest repeat content in genome sequence, lower number of pseudogenes and higher number of species-specific gene when compared to the human genome. The zebrafish genome shares high homology with the human genome, with approximate 70% of human genes having at least one zebrafish orthologue.