Morphogenesis stages of the embryonic development of the Levantine viper (Macrovipera lebetina obtusa Dwigubsky, 1832)

The article provides information on the embryonic development of the Levantine viper (Macrovipera lebetina obtusa Dwigubsky, 1832), its stages of morphogenesis, and the morphological variability of embryogenesis at the time of ovulation. It was determined that on the day of egg laying, the blood vessels of the provisional organs (allantois and yolk sac) were formed and covered 50-60% of the body surface of the embryo, and the embryos are already in the initial stages of embryonic development morphogenesis (spiral twist of the body and the beginning of the formation of the tongue). It was determined that the Levantine viper has already finished the 33-35 day development period (embryonic period) in the oviducts by the time of ovulation. After the egg was laid outside, the morphogenesis stages of embryonic development during the natural incubation period were determined according to the morphology of the embryos and the level of development of provisional organs, and 7 stages were described. As a result of the morphological study, 4 periods were distinguished in the embryonic development of the Levantine viper: embryo, pre-fetus and fetus (morphogenesis), and hatching periods. The article describes the morphology and development process of embryos in the stages of morphogenesis and embryonic development.