Participation of Na+/K+-ATPase and aquaporins in the uptake of water during moult processes in the shrimp Palaemon argentinus (Nobili, 1901).

Due to the presence of the exoskeleton, the moult cycle is a required event in the life of crustaceans. In order for the exoskeleton to be replaced, it is necessary for these animals to uptake water from the environment for their body tissues during the late pre-moult, ecdysis and in the early post-moult for the expansion of the new cuticle. The mechanisms and organs used to uptake water in these events are not yet completely clear. In this study, we investigated the participation of aquaporins and Na+/K+-ATPase in cells of two potential organs responsible for the uptake of water (gills and gut) at three different stages of the moult cycle in freshwater shrimp Palaemon argentinus. We showed the participation of these two proteins with different functional patterns in gills and intestinal cells as water uptake pathways for moult and early post-moult. Our results indicate that Na+/K+-ATPase promotes the necessary osmotic gradient in the gills for water uptake through the gut cells during the pre-moult. This process, in turn, remains active during the post-moult stage with the addition of water influx through the gill cells.