Abstract: | Application of the Schiff's reagent on fresh and undecalcified cuticle of crustaceans such as Emerita asiatica and Ocypoda platytarsis showed positive results with their calcified layer which led to suggest that salts of calcium account for the staining. In vitro studies with carbonate and other salts furnished confirmatory evidence. It is suggested that in tests involving the Schiff's reagent proper removal of resident salts must be carried out. |