Ontogenic maturation and gene expression in Procambarus clarkii

Crustaceans have a cyclic phenomenon, moulting, for development and growth that is not encountered in most other groups of aquaculture animals. Biochemical and physiological changes in various tissues of crustaceans occur during the moult cycle. Changes to the immune components of prawns in association with moulting have also been studied to a lesser extent. Hematological variation in both total hemocyte count (THC) and differentiated hemocyte count (DHC) was recorded in individuals and between species during the moult cycle. In the current investigation, we characterized the different classes of circulating blood cells in Procambarus clarkii by means of light, electron microscopy, RT-PCR, and western blot analysis. The red swamp crayfish, P. clarkii was examined for hemocytes distribution in relation with moult cycle (Postmoult, A,B; Intermoult, C; Premoult, D0/D1, D2/D3). Effect of moult cycle on the lymphoid organ spheroid (LOS) cells of P. clarkia was also studied. The changes in the histological organization of lymphoid organ and characterization of lymphoid cells after infection with white spot syndrome virus (WSSV) in P. clarkii were investigated.