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

摘要

Maturing Atlantic salmon, transferred from brackish watertwo weeks prespawning, were held under four different temperatureand salinity regimes through their spawning period.Values of blood glucose and haematocrit were measured everyweek during this period. Inorganic components (K+ and Cl-) wereanalysed from coelomic fluid, blood and seminal plasma.The dry matter of the eggs at spawning, were measured. Themortality of the broodfish and the eyed eggs were also recorded.Cold seawater was the most unfavourable environment to thebroodfish, as they suffered high mortalities and high levels ofchloride, potassium and blood glucose. These results probablyreflected problems with osmoregulation. Cold brackish waterappeared to be the best environment to both eggs and broodfish,although the males had problems at low temperatures. The haematocritvalues were highest among males, but decreased among bothmales and females during the investigation period. Neither haematocrit,nor the dry matter of the eggs seemed to be affectedby this short time exposure to different water qualities.