Fig. 6

Histopathological changes in the hepatopancreas, gill and muscle. Hepatopancreas of the Macrobrachium nipponense following a 7-day exposure to hypoxia: (a) control prawns; (b) prawns exposed to hypoxia at 2.5 mg/L dissolved oxygen, showing the appearance of large numbers of vacuoles in the tubular epithelial cells and abnormal lumens. ALU, abnormal lumen; MEL, melanization of cells; REC, ruptured epithelial cells. Anterior gill lamellae of the M. nipponense following a 7-day exposure to hypoxia: (c) control prawns showing normal lamellae structure and intact pillar cells (PC); (d) prawns exposed to hypoxia at 2.5 mg/L dissolved oxygen showing disrupted pillar cells (PC*), necrosis (NCR) and extensive infiltration of haemocytes (HAE). Histological cross sections of muscle of (e) control group and (f) prawns exposed to hypoxia at 2.5 mg/L dissolved oxygen showing simialr striated muscle fibers infiltrated by hemocytes (small arrowhead). Scale bars = 50 μm