Ultra-structure of Ionocyte cells in gills of Silurus glanis of Mahabad Dam, Kordestan Province

Gills of catfish Silurus glanis (300 g weight) of Mahabad Dam (Iran) were examined for structural attributes in 2004. Immediately after catch, gills were removed and placed in Bouin and Glutaraldehyde for structural and microscopic examinations. For classical histological assessment, samples were stained with Hematoxylin and Eosin and examined under light microscope. For electron microscopy, cuts 90 nanometers each were prepared and stained with Uranyl Acetate and Lead Citrate, covered with silver, examined and photographed. We found the gill cells being composed of ionocyte alpha, beta, accessory, mucous, pillar and mosaic cells. The ionocytes were located at the base of the gill rakers and intra raker spaces. These structural attributes of ionocyte cells demonstrate their active role in osmotic regulation of catfish