the adaptation of P. monodon to both low and high salinity environments. The antennal glands of shrimps reared in 7 ppt seawater exhibit several ultrastructural alterations, including greater ramification of the cytoplasmic processes of the podocytic cells and dilation of the inter-podocytic spaces (Fig. 1), more mitochondria in the basal striation of the labyrinth cells, and more cell debris in the labyrinth lumens (Fig. 3), compared with animals maintained at 15 ppt salinity.