What are the different types of osmoregulation in different organisms?

There are two types of osmoregulation based on the mechanism that different organisms use to regulate water and solute balance. 

1. Osmoconformers are organisms that try to match the osmolarity of their body with their external environment, either actively or passively. In these organisms, the osmotic pressure inside the body is the same as that of their surroundings. Most marine invertebrates including starfish, jellyfish, scallops and lobsters are osmoconformers. These organisms do not actively regulate their internal osmolarity. Instead, they allow their internal osmolarity to match their osmolarity of their surroundings so that their internal and external environments are identical.  
2. Osmoregulators are organisms that actively regulate their osmotic pressure, independent of the external environment. In these organisms, the internal osmolarity is different from that of the surroundings. Osmoregulators use various methods, including behavioral and physiological adaptations, to actively maintain their internal environment. Freshwater fish and most vertebrates, including humans, are osmoregulators. Freshwater fish actively control salt concentrations despite the presence of salt in the surrounding environment. In humans, the kidneys use the process of filtration to actively maintain the body’s internal osmotic pressure.