What is meant by osmoconformer?
An osmoconformer is a marine invertebrate (with the exception of the Atlantic Hagfish) that maintains its internal salinity such that it is always equal to the surrounding seawater. Osmoconformers do not actively exchange solutes with the environment, but keep their body fluids isotonic to the external environment by actively regulating their internal concentration of amino acids, ions, and proteins to match the osmolarity of the environment. Marine invertebrates as well as hagfish and elasmobranchs, which are vertebrates, are osmoconformers, but have higher concentrations of divalent ions (SO42-, Ca2+, Mg2+) and lower Na+ and Cl- than the surrounding sea water.
