The pre- and postembryonic development of Artemia franciscana (Anostraca: Artemiidae)

Artemia franciscana is a universal live feed in aquaculture, and it has been reported as an invasive species in many Asian hypersaline ecosystems. The present observations illustrated the pre- and postembryonic development stages of the A. franciscana population confined to the Indian saltern of Kelambakkam. We observed their growth patterns during various hydration periods with specific time intervals. Results showed differences in the development stages with respect to unique identity. Interestingly, a period of hydration showed notable cellular movement toward clockwise positions in the hydrating cysts. After 10 h of hydration, blastocoel appeared, accelerating the dynamic route of nuclei movement. At the end of the invagination, the embryo burst out of the cyst, and a sequence of emerging stages was noted. With reference to light microscopic observations, a series of developmental stages were observed, and each instar was documented by developing limb buds of nauplii. Excitingly, the 10th and 11th instar stages reveal sexual differentiation between male and female individuals. Thus, the laboratory culture study clearly documented the different developmental stages with their specific characteristic features. However, further molecular study would provide a cellular basis for understanding the early development of A. franciscana.