Tag Archives: osmoregulation

Blood ionic composition in marine elasmobranchs and holocephalans is some what higher than in teleosts, but its osmolarity is very much higher, close to that of seawater. This is because the blood contains, in addition to the usual ions, large amounts of low-molecular weight nitrogenous solutes, chiefly urea. First found …

Vacuoles can be seen by light microscopy in the cytoplasm of many protozoa. Some of these vacuoles periodically fill with a fluid substance that is then expelled. Evidence is strong that these contractile vacuoles function principally in osmoregulation. They are more prevalent and fill and empty more frequently in freshwater …