Environmental influences on regulation of blood plasma/serum components in teleost fishes: a review

摘要

Concentrations of both inorganic and organic blood plasma/serum components of teleost fishes were reviewed in seven habitat/life-history categories. These were: freshwater; inland saline; estuarine and nearshore marine; pelagic and deep-sea; diadromous; southern cold-water; and northern cold-water. Plasma/serum osmolalities were compared among groups acclimated to/living in fresh and in salt water. Contributions of inorganic ions and colligative and non-colligative organic molecules were evaluated including with respect to melting and freezing points, and antifreeze activity of plasma/serum in species from cold marine waters. Possible roles of TMAO in deep-water fishes were reviewed. Discussion also included influences of ambient salinity and temperature on concentrations of plasma/serum components. Seasonal cycles of blood plasma/serum components were discussed, along with antifreeze concentrations in other body fluids and tissues of cold-water fishes. Regulatory patterns of plasma/serum osmolalities were compared among the most euryhaline of teleosts evaluated here. Highest mean values of plasma/serum osmolalities in sea water were seen in southern cold-water and in pelagic and deep-sea fishes. The southern cold-water group also had the lowest plasma/serum freezing points among these groups. Comparisons of mean plasma/serum Na and Cl concentrations among fishes from fresh waters did not differ significantly among groups, but species from cold marine waters showed higher levels than did other groups in marine waters. Plasma/serum osmotic, Na and Cl concentrations of these seven groups of teleosts were compared with those of other fish-like vertebrate groups. Possible impacts of global warming on regulatory responses of plasma/serum components were discussed.