Abstract
The article describes the study of Rodlet cells in gills of 15 fish species of the Cyprinidae family, 1 fish species from the Siluridae family, 2 fish species from the Percidae family, and 1 fish species from the Esocidae family, all caught in Zhaiyk River, Republik of Kazakhstan. Rodlet cells at the present stage of researche are classified as the cells of nonspecific immune response in fish. Besides, they can be used as biomarkers to monitor the state of water reservoirs. Serious pathological changes in gills of the surveyed fish were revealed by histomorphological technique, indicating the pollution of water environment. An increased number of Rodlet cells was associated with morphological aterations in the gills. It was also noted that in the gills of all species Rodlet cells are at the different stages of differentiation. Data obtained support the issue of protective and adaptive functions of Rodlet cells under adverse environmental conditions.