Abstract: | Chronological study of the larval development of the chiton Deshayesiella curvata with sketching of the first stages of egg division and embryos up to the seven-valved shell stage is presented for the first time. D. curvata exhibits pelagic development with lecithotrophic larvae. Larval eyes form at the age of 3 days; at the age of 6 days, a Schwabe organ appears near the eyes in the form of two pigmented spots. Chitons at the stage of seven-valved shell have larval eyes, as well as the Schwabe organ. |