Sharks are able to maintain their fluids hypertonic to the ocean environment by accumulating: (Choose One) A. fluids in the rectal gland B. fluid in the organ of Lorenzini C. Calcium and phosphate D. urea and TMAO Solution Ans D urea and TMAO sharks store urea and TMAO ( trimethyl amine oxide). Urea is responsible for the metabolism of different compounds in their body and help to excrete nitrogen out from their body..