Inhibition of Atlantic Salmon (Salmo salar) Hatching at Low pH

Abstract

Hatching of Atlantic salmon (Salmo salar) eggs was delayed or prevented if they were exposed to water of lowered pH (4.0–5.5) after eye pigmentation had developed. Hatching subsequently could be induced by returning eggs to normal pH levels (6.6–6.8). Perivitelline pH fell rapidly to near ambient levels when eggs were exposed to low pH. It is suggested that the observed effects on hatching were due to inhibition of the hatching enzyme, chorionase.Key words: Atlantic salmon, eggs, pH, perivitelline fluid, chorionase