The effect of illumination on alevins of Atlantic salmon (Salmo salar) and rainbow trout (S. gairdneri), incubated on different substrates
Original version
This report is not to be cited without prior reference to the authorsAbstract
Atlantic salmon (Salmo salar) and rainbow trout (S. gairdneri)
eggs were incubated in plexi-glass aquariums. After hatching,
alevins were kept in darkness, two groups of each species without
substrate, two groups in gravel and two groups in Astroturf
artificial substrate. Every three days after hatching, heartfrequencies
or respirationrates were counted as measure of different
activity and stress in the various groups, following a 10 minutes
exposure to light. The respiration rate and heartbeat frequence of Atlantic
salmon alevins was generally lowered among all the groups, during
the period of observation. The alevins reared in Astroturf, showed
however the lowest and most stable respiration rate and
heartbeat frequence, due to their low activity at the bottom of
the aquariums.