The effect of a short time exposure to different temperature and salinity regimes on survival of maturing Atlantic salmon and eyed eggs, and changes in blood and seminal plasma during the spawning period
Original version
This report is not to be cited without prior reference to the authorsAbstract
Maturing Atlantic salmon, transferred from brackish water
two weeks prespawning, were held under four different temperature
and salinity regimes through their spawning period.
Values of blood glucose and haematocrit were measured every
week during this period. Inorganic components (K+ and Cl-) were
analysed from coelomic fluid, blood and seminal plasma.
The dry matter of the eggs at spawning, were measured. The
mortality of the broodfish and the eyed eggs were also recorded.
Cold seawater was the most unfavourable environment to the
broodfish, as they suffered high mortalities and high levels of
chloride, potassium and blood glucose. These results probably
reflected problems with osmoregulation. Cold brackish water
appeared to be the best environment to both eggs and broodfish,
although the males had problems at low temperatures. The haematocrit
values were highest among males, but decreased among both
males and females during the investigation period. Neither haematocrit,
nor the dry matter of the eggs seemed to be affected
by this short time exposure to different water qualities.