Influence of Varying pH and some Inorganic Cations on the Perivitelline Potential of Eggs of Atlantic Salmon ( Salmo salar )

A potential difference is maintained between the perivitelline fluid of the Atlantic salmon (Salmo salar) egg and the incubation medium. The magnitude of this potential difference depends on the ionic composition of the incubation medium; it exhibits a maximal negativity in deionized water, then dep...

Full description

Bibliographic Details
Published in:Canadian Journal of Fisheries and Aquatic Sciences
Main Author: Peterson, R. H.
Format: Article in Journal/Newspaper
Language:English
Published: Canadian Science Publishing 1984
Subjects:
Online Access:http://dx.doi.org/10.1139/f84-124
http://www.nrcresearchpress.com/doi/pdf/10.1139/f84-124
Description
Summary:A potential difference is maintained between the perivitelline fluid of the Atlantic salmon (Salmo salar) egg and the incubation medium. The magnitude of this potential difference depends on the ionic composition of the incubation medium; it exhibits a maximal negativity in deionized water, then depolarizes, and finally reverses in sign as the ionic content of the incubation medium is raised. The potential difference obeys the Nernst relationship over a limited concentration range of H + , Ca 2+ , and Mg 2+ (10 −5 to 10 −3 M). The maximal change in potential difference with change in Na + and K + concentrations is less than that predicted by the Nernst equation. The potential difference permits calculation of the degree of concentration of cations in the perivitelline fluid over that of the ambient medium. Depolarizing the perivitelline potential by lowering the ambient pH will result in losses of other cations from the perivitelline fluid.