A New Cleaning Method for Accurate Examination of Freshwater Gastropod Shell Specimens Covered with Iron-rich Deposits

Sodium hypochlorite has been used for cleaning specimens of freshwater and brackish water snails that are covered with deposits. Our experiments using two snail species, Semisulcospira niponica (Smith, 1876) S. reticulata Kajiyama Habe, 1961, showed this traditional method could remove thin deposit layers, including algae, but was not useful obstinate We found a new ammonium thioglycolate be applied to iron-rich Though treatment caused loss gloss inside the aperture, prevented by plugging kneaded eraser into an aperture. Moreover, clean little damage periostracum. So as deposits least shells, 3% w/v sodium 20% suitable Degeneration microstructure inner whorls can avoided plugged shell apertures in both methods. Shell composed algae iron should treated first thioglycolate, then Appropriate methods enable accurate examination long-term preservation specimens.