Question

what is difference b/w osmoconformers and osmoregulators?

Answer 1

Two major types of osmoregulation are osmoconformers and osmoregulators. Osmoconformers match their body osmolarity to their environment . It can either be active or passive. Most marine invertebrates are osmoconformers, although their ionic composition may be different to that of seawater. 

Osmoregulators tightly regulate their body osmolarity which always stays constant and are more common in the animal kingdom. Osmoregulators actively control salt concentrations despite the salt concentrations in the environment. An example is freshwater fish. The gills actively uptake salt from the environment. Water will diffuse into the fish so it excretes a very hypotonic urine to expel all the excess water. A marine fish has an internal osmotic concentration lower than that of the surrounding seawater so it tends to lose water and gain salt. It actively excretes salt out from the gills. Most fish are stenohaline, which means they are restricted to either salt or fresh water and can cannot survive in water with a different salt concentration than they are adapted to. However, some fish show a tremendous ability to effectively osmoregulate across a broad range of salinities; fish with this ability are known as euryhaline species.
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