Characterization of the histologic appearance of normal gill tissue using special staining techniques.

Anatomic pathologists are familiar with stains used in light microscopy to identify cells, storage products, tissue deposits, and pathogens. Assessment of the surrounding tissue with special stains may reveal aspects of interest for the tissue or the species. We illustrate the expected staining characteristics of normal rainbow trout gill tissue with routine hematoxylin and eosin and 18 other histochemical stains.