Diffusion of chloride ions in the mucus on the oesophagus of Enophrys bison, a marine teleost fish.

Microelectrodes sensitive to Cl- have been used to estimate the diffusion coefficient for Cl- in the mucus on the oesophagus of a marine teleost fish, Enophrys bison. The estimate was 0.231 X 10(-5) cm2s-1. This value is significantly less than the value in saline or in seawater. The technique was based on a simple interpretation of Ficks 1st law. The flux of Cl- across an isolated, everted preparation of oesophagus was compared to the concentration gradient of Cl- within the mucous layer and its thickness and the surface area of the preparation available to diffusion.