Fish react with detachment of the mucous membrane in diverse situations, like e.g. sudden and severe changes in salt levels. Changes in water conditions cause the same result. Detachment of the mucous membrane in itself is not a problem if the mucous membrane can regenerate immediately, since it prevents infections from penetrating and tries to ward off ectoparasites. When fish are infected with ectoparasites, it is even beneficial to have the fish react with a regeneration of the mucous membrane when changes in salt levels occur. If the parasites have settled in the fish's mucous membrane, they will be emitted into the water where they can be killed by a suitable remedy.