Ionic composition of the plasma and whole blood of marine and fresh water eels, Anguilla rostrata

Abstract

1. 1. The concentrations of sodium, potassium and chloride of the plasma and whole blood from marine- and fresh water-acclimated eels were determined. 2. 2. The mean concentrations of these ions in the plasma and whole blood of the marine eels were greater than in the fresh water eels; the mean hematocrit for marine eels was less than that of the fresh water eels. 3. 3. Significant differences were demonstrated between the plasma sodium and chloride and whole blood chloride of the two groups. 4. 4. Calculated intra-erythrocytic ion concentrations indicate that the ionic composition of the erythrocyte is altered by changes in ambient salinity.