The research was conducted from May to September 2025 in the aquarium complex of Baku State University. Danio rerio Hamilton, 1822 breeders, was used as the model research object. Their fertilized eggs were obtained under aquarium conditions, and their embryonic and post-embryonic developmental stages were studied. The duration of individual stages in the embryonic development of Danio rerio was determined: zygote (0-0.75 hours), cleavage (0.75-3.5 hours), blastula, characterized by the formation of the blastodisc (3.5-7.5 hours), gastrula, accompanied by the migration of cells of the southern pole and the formation of the three primary germ layers (ectoderm, mesoderm, and endoderm) (7.5-14 hours), somite formation (14-32 hours), organogenesis and twitching stages beginning with the heartbeat, as well as the hatching of free embryos from the eggs (50-75 hours). The effects of live and mixed feeds on the development of Danio rerio fry were studied comparatively. The creation of a complete chronological and morphological map of Danio rerio development can provide a reliable database for future research. The results obtained can be used in the educational process (as visual aids and information sources in the teaching of biology, embryology, and ichthyology), in scientific research, and in aquarium complexes (for the effective breeding of the species and obtaining healthy offspring).