Osmotic and ionic regulation in embryos, alevins and fry of the five species of Pacific salmon ...

• Main Author: Weisbart, Melvin
• Format: Text
• Language: English
• Published: University of British Columbia 2011
• Subjects: Oncorhynchus gorbuscha
• Online Access: https://dx.doi.org/10.14288/1.0104785; https://doi.library.ubc.ca/10.14288/1.0104785

The major purpose of this study was to examine the physiological basis of the differences in the early life histories of pink Oncorhynchus gorbuscha, chum O. keta, coho O. kisutch, chinook O. tshawytscha and sockeye O. nerka. To this end, the following working hypotheses were tested: (i) the embryo, alevin and fry of pink and chum salmon are euryhaline, whereas the same life stages of coho, chinook and sockeye are stenohaline and (ii) the euryhalinity of pink and chum is due not to high tissue tolerance but to their ability to regulate the osmotic and ionic concentrations in their blood, whereas the stenohalinity of coho, chinook and sockeye stems from their inability to osmoregulate and ion regulate. The results did not completely support these hypotheses. The LD₅₀ values and the osmoregulatory data obtained from embryos indicated that pink and chum are not euryhaline as hypothesized but like coho, chinook and sockeye embryos are stenohaline. However, pink and chum embryos showed significantly greater ...