Embryo Movements of Atlantic Salmon (Salmo salar) as Influenced by pH, Temperature, and State of Development

Abstract

Two types of embryo movements of Atlantic salmon (Salmo salar), pectoral fin flutter and trunk movements, were measured as a function of incubation temperature, pH, and developmental state. Trunk movements began at 200 degree-days, initially at highest frequency. The frequency decreased throughout subsequent development and then increased slightly just before hatching. Movements were much more stereotyped in the earliest stages of development than just prior to hatching. Frequencies at 200 degree-days were insensitive to temperature and pH. Frequencies just prior to hatching were very temperature sensitive (Q10 of 13) and were decreased at low pH. This decreased frequency may be related to documented effects of temperature and low pH on hatching. Pectoral fin movements were temperature sensitive (Q10 of 2) and pH insensitive. These movements were initiated at 350 degree-days of development and attained maximal frequency at 400 degree-days.