Salt Gland: A compound tubular gland, located around the eyes and nasal passages in marine animals and birds, the physiology of which figures in water-electrolyte balance. The Pekin duck serves as a common research animal in salt gland studies. A rectal gland or rectal salt gland in the dogfish shark is attached at the junction of the intestine and cloaca and aids the kidneys in removing excess salts from the blood. (Storer, Usinger, Stebbins & Nybakken: General Zoology, 6th ed, p658)DucksVasotocin: A nonapeptide that contains the ring of OXYTOCIN and the side chain of ARG-VASOPRESSIN with the latter determining the specific recognition of hormone receptors. Vasotocin is the non-mammalian vasopressin-like hormone or antidiuretic hormone regulating water and salt metabolism.4-Nitrophenylphosphatase: An enzyme that catalyzes the hydrolysis of nitrophenyl phosphates to nitrophenols. At acid pH it is probably ACID PHOSPHATASE (EC; at alkaline pH it is probably ALKALINE PHOSPHATASE (EC EC and Crocodiles: Large, long-tailed reptiles, including caimans, of the order Loricata.Salts: Substances produced from the reaction between acids and bases; compounds consisting of a metal (positive) and nonmetal (negative) radical. (Grant & Hackh's Chemical Dictionary, 5th ed)GeeseRenal Plasma Flow: The amount of PLASMA that perfuses the KIDNEYS per unit time, approximately 10% greater than effective renal plasma flow (RENAL PLASMA FLOW, EFFECTIVE). It should be differentiated from the RENAL BLOOD FLOW; (RBF), which refers to the total volume of BLOOD flowing through the renal vasculature, while the renal plasma flow refers to the rate of plasma flow (RPF).Salivary Glands: Glands that secrete SALIVA in the MOUTH. There are three pairs of salivary glands (PAROTID GLAND; SUBLINGUAL GLAND; SUBMANDIBULAR GLAND).Water-Electrolyte Balance: The balance of fluid in the BODY FLUID COMPARTMENTS; total BODY WATER; BLOOD VOLUME; EXTRACELLULAR SPACE; INTRACELLULAR SPACE, maintained by processes in the body that regulate the intake and excretion of WATER and ELECTROLYTES, particularly SODIUM and POTASSIUM.Sodium-Potassium-Exchanging ATPase: An enzyme that catalyzes the active transport system of sodium and potassium ions across the cell wall. Sodium and potassium ions are closely coupled with membrane ATPase which undergoes phosphorylation and dephosphorylation, thereby providing energy for transport of these ions against concentration gradients.Fresh Water: Water containing no significant amounts of salts, such as water from RIVERS and LAKES.