Most fish are stenohaline, which means they are restricted to either salt or fresh water and cannot survive in water with a different salt concentration than they are adapted to. It actively excretes salt out from the gills. A marine fish has an internal osmotic concentration lower than that of the surrounding seawater, so it tends to lose water (to the more negative surroundings) and gain salt. Water will diffuse into the fish, so it excretes a very hypotonic (dilute) urine to expel all the excess water. The gills actively uptake salt from the environment by the use of mitochondria-rich cells. ![]() Osmoregulators actively control salt concentrations despite the salt concentrations in the environment. Osmoregulators tightly regulate their body osmolarity, which always stays constant, and are more common in the animal kingdom. Most marine invertebrates are osmoconformers, although their ionic composition may be different from that of seawater. Osmoconformers match their body osmolarity to their environment actively or passively. Two major types of osmoregulation are osmoconformers and osmoregulators. Osmotic pressure is a measure of the tendency of water to move into one solution from another by osmosis. The osmotic pressure in the body is homeostatically regulated in such a manner that it keeps the organism's fluids from becoming too diluted or too concentrated. Osmoregulation is the active process by which an organism maintains its level of water content.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |