Changes in the EEL intestine during seawater adaptation

Abstract

1. 1. Rate of fluid absorption by eel ( Anguilla rostrata) intestinal sacs in vitro reached seawater adapted values 3 days after transfer from freshwater to seawater. 2. 2. After 3 days in seawater oxygen consumption and Na-K-ATPase activity of intestinal mucosa had not increased over freshwater values. 3. 3. The weight of intestinal mucosa increased 32% during seawater adaptation as a result of an increase in the number of mucosal cells (hyperplasia). 4. 4. The rate of intestinal fluid absorption was reduced by 10 −4 M ouabain and was not affected by 10 −4 M acetazolamide.