Universal Method for Preparing, Sectioning, and Polishing Fish Otoliths for Daily Ageing

摘要

The document describes a technique for preparing, sectioning and polishing fish otoliths for daily ageing. The authors have developed a methodology that allows thin sections to be made on any size otoliths in any plane and describe it in detail. Briefly, the otolith is embedded in polyester resin. After curing, the embedded otolith is precisely aligned and mounted on a glass slide and sectioned with a low speed saw. The section is removed, attached to another slide with thermoplastic resin, and polished by hand using a descending series of abrasive papers. When the primordia is reached, if needed, the section is heated, turned and polished from the opposite side. Etching with HCl or EDTA is helpful for light microscopy and mandatory for SEM.