A chemical way of thinning otoliths of adult Atlantic herring ( Clupea harengus ) to expose the microstructure in the nucleus region

Abstract

The thickness of adult herring ( Clupea harengus ) otoliths was reduced chemically through selective decalcification in contrast to physical grinding. Microstructure around the nucleus was clearly visible under a light microscope after the preparation. The process of this technique included three steps: first, the two ridges along either side of the sulcus were roughly ground; second, the otolith exterior side was brought down to the midplane by decalcification; finally, the decalcification of the exterior side was prevented while the interior side was further decalcified to produce a thin section, which was then mounted on a glass slide and studied.

Author notes

Present address: Pacific Biological Station, Nanaimo, British Columbia, Canada V9R 5K6.