Abstract:Garra mirofronits is classified under the order Cypriniformes, family Cyprinidae, subfamily Labeoninae, and genus Garra. This species is endemic to the Lancang River and is exclusively found in the middle and lower reaches of the river within China. Its distribution is confined to an altitude range of 500‒700 meters above sea level, and its wild populations have declined. G. mirofronits exhibits a cylindrical body shape with a distinctive frontal groove anterior to the nostrils, which forms two frontal processes. Each process terminates in a prominent conical keratinous projection. This species prefers habitats characterized by swift currents and rocky substrates, where it adheres to rocks using its adhesive discs and primarily feeds on filamentous algae. In recent years, the progressive development of the Lancang River, including the construction and operation of hydropower stations, has altered the river's hydrological conditions, thereby impacting the migratory, reproductive, and feeding behaviors of fish. Notably, the decrease in flow velocity and the reduction in the length of flowing water have severely compromised the hatching success of drifting eggs, including eggs of G. mirofronits. Consequently, the wild populations of G. mirofronits have experienced a significant decline, necessitating urgent conservation measures. This study aims to investigate the temporal characteristics of the early development of G. mirofronits, enrich research data on its reproductive and developmental biology, and offer technical support for artificial breeding and large-scale seedling production of this species. Sexually mature individuals of G.mirofronits were collected from the wild and used to obtain fertilized eggs through artificial induction of ovulation and dry insemination. Then, the early development process of the fertilized eggs was observed and recorded in detail. Three artificial breeding experiments were carried out in total. On average, the ovulation induction rate was 100%, the fertilization rate was (89.93±0.72)%, and the hatching rate was (87.83±1.00)%. The fertilized eggs were light gray, with a thin and transparent egg membrane, non-viscous, and a diameter of (1.12±0.04) mm. After water absorption and expansion, the egg membrane diameter reached (3.37±0.09) mm, with an expansion coefficient of 300.89%. At water temperatures between 18‒21 ℃, hatching occurred after 24‒26 hours, with an accumulated hatching temperature of 496.04 ℃·h. The early development process went through nine stages including fertilized egg, blastoderm stage, cleavage stage, blastula stage, gastrula stage, neurula stage, organogenesis stage, heartbeating stage, and hatching stage. The total length of newly hatched larvae was (4.50±0.07) mm, with 32 myotomes. The period of the yolk sac larvae lasted for 5 days, with the specific growth rate of the total length at 9.22%/d. The larval stage lasted for a total of 16 days, with the specific growth rate of the total length at 7.02%/d. The temporal characteristics of the early development of G.mirofronits follow the basic laws of osteichthyes development and are in line with the general characteristics of the embryonic development of drifting eggs. It is thus a typical fish species that produces drifting eggs.