Virtually every major medical advance of the last century and at still has depended upon research with animals. Zebrafish's journey from the ocean to the laboratory leads to major scientific breakthroughs. Transparency structure of zebrafish helps in monitoring their internal structures and are permitting scientist to see effectes of nano particles in fish. Their organs share the same main features as humans and so can be used to study human developmental processes. Zebrafish congruence 70% of their genes with humans, and 84% of ailment-depended genes have zebrafish congruence. The zebrafish embryos can also genetically modified. Certain fishes like zebrafish are able to regenerate damaged retinal nerve cells. Müller galia cells in retina of zebrafish can transform in response to injury and act like stem cells to regrow the retina and replace all damaged neurons. Though humans have the same exact Müller galia cell, they don’t respond to damaged in the same way. Zebrafish are also very responsive to having their genomes edited. Zebrafish regenerate some tissue such as heart in during larval stage. In additionaly zebrafish are used as an animal model to study pharmocology – how drugs work and what they do to an organism’s body. Aim of this review, here, we review current knowledge of how these specialized structures and model organism by focusing on cellular behaviors and molecular mechanisms, highlighting findings from in vivo models and briefly discussing the recent advances in tissue cell culture and organoids. Review discusses the applications of human organoids models of disease on model organism and outlines the ailment treatments.