Research often utilizes patients' cells or tissue samples, but to determine if a mutation in a specific gene can cause a patient's symptoms, we often need experimental animal models. In the wild, they are found in rivers and ponds of India; however they are now often available in pet shops. As a result, they take up much less space than mice and are cheaper to maintain. This is very different from a mouse. Scientific experiments are usually repeated several times to prove that the results are correct. Therefore, it is useful to have animals that can repeatedly produce a large number of offspring. Zebrafish embryos are easily manipulated in a variety of ways, as they are also subjected to in vitro fertilization. If desired, in vitro fertilization can be performed. Eggs fertilized at the single-cell stage can be easily injected with DNA or RNA to permanently alter the genetic makeup and create transgenic or knockout zebrafish lines. Manipulating the mouse this way is much more complicated. Mouse embryos develop inside the mother's body, and to access and manipulate them, the mother must be sacrificed. To keep the embryo alive after fertilization or injection, it must also be transferred to another female mouse. Plus, zebrafish embryos are transparent, allowing scientists to see under a microscope as fertilized eggs develop into fully formed baby fish. Their transparency also allows visualization of fluorescently labeled tissues in transgenic zebrafish embryos. Mouse embryos are not transparent and develop inside the mother's body, so we cannot observe the development of live embryos like we can in zebrafish. However, there are limits to the types of diseases that can be studied in zebrafish. Human diseases caused by genes absent in zebrafish require other animal models. Furthermore, zebrafish are not useful models for human diseases that occur predominantly in tissue types or body parts that zebrafish do not possess. Zebrafish have many advantages as a model in human pediatric research. Given the physical and ethical issues of conducting experiments on human patients, biomedical research uses model organisms to explore biological processes that are conserved between humans and lower vertebrates. has focused on researching The most common model organisms are small mammals, mostly rats and mice. Although these models have significant advantages, they are expensive to maintain, difficult to manipulate embryos, and have limitations for large-scale genetic studies. The zebrafish model successfully complements these shortcomings in experimental mammalian models. The low cost, small size, and external development of zebrafish make it an excellent model for vertebrate developmental biology. Techniques of large-scale genomic mutagenesis and gene mapping, transgenesis, protein overexpression or knockdown, cell transplantation and chimeric embryo analysis, and chemical screening have increased the power of this model organism immeasurably. It is now possible to rapidly determine the developmental function of genes of interest in vivo and identify genetic and chemical modifiers of the processes involved. Findings made in zebrafish can be further validated in mammals. With new techniques being developed regularly, zebrafish are poised to make significant advances in our understanding of vertebrate development under normal and pathological conditions.