A Re-Examination of the Osmotic Properties of the Pacific Hagfish, Polistotrema Stouti

Determinations of the osmotic pressure of whole blood and serum show that Polistotrema stouti is isotonic in sea water concentrations from 85 to 116%. 2. Hypertonicity of the blood can be induced experimentally by disturbance of the animals. This factor could account for hypertonic values reported previously. 3. Serum sodium and chloride account for 88% of the total osmotic pressure. The mean Cl1/Cle ratio equals 0.92. The hypertonicity which can be produced by disturbance is reflected by a rise in the serum sodium and chloride concentrations. 4. Urea is absent from the liver and is considered to have no significance in the osmotic composition.