Birds That Live in Marine Environments and Thus Lack Access

Question

Birds that live in marine environments and thus lack access to fresh drinking water
A)osmoregulate without using a transport epithelium for this purpose.
B)drink sea water and secrete excess ions through their kidneys only.
C)drink sea water and secrete excess ions mainly through their nasal salt glands.
D)have plasma that is isoosmotic to ocean water.
E)obtain water by eating only osmoregulating prey.

Accepted Answer

Birds that live in marine environments lack access to fresh drinking water, so they must drink sea water to fulfill their water needs. However, sea water contains high concentrations of salt ions, which can be harmful to their bodies. To remove excess salt ions, marine birds have nasal salt glands that secrete concentrated salt solutions out of their nostrils. This process is known as salt excretion or nasal salt gland secretion. Therefore, marine birds primarily secrete excess ions through their nasal salt glands.