Osmoregulation and electrolyte balance in a fully marine mammal, the dugong (Dugong dugon).

Dugongs (Dugong dugon) are fully marine mammals that live independently of fresh water so must balance water and electrolytes in a hyperosmotic environment. To investigate osmoregulation, matched plasma and urine from 51 live wild dugongs were analysed for osmolality, major electrolytes (Na, Cl, K), urea, creatinine, and glucose. Maximum urine osmolality (1468 mOsm kg ) and Na, K, and Cl concentrations (757, 131.