Aishpur O. Microscopic structure of perch and roach in normal and at posthodiplostomose

The thesis is based on experimental studies and presents studying of the prevalence of posthodiplostomose in fish in the basin of river Dniester on the territory of Khmelnitsky region. Described clinical signs of the disease in perch and roach, pathological changes, and also clarified the microscopic structure of organs and tissues of two species of fish. It is shown that in the fish in the river Dniester on the territory of Khmelnitsky region parasitic diseases account for 97.54 % of all diseases of different etiologies (parasitic, viral, bacterial and fungal infections). Among parasitic diseases most frequently diagnosed posthodiplostomose. The main clinical symptom at posthodiplostomose is presence on different parts of the body of affected fish black spots. In perch number of lesions on the body is significant (90.5±40 per fish), and black spots do not exceed the diameter of 2 mm. In roach on the body detected a significantly lower amount of lesions (6.5±2 per fish) and their size in comparison with perch is significantly larger (3–4 mm and sometimes more). During the histological examination found that in the process of investing around the parasite forms cysts. First formed a single layer cyst, consisting of one or two rows not clear contoured cells with large, not very intensely painted with hematoxylin nuclei elongated or oval form. Then, the newly formed cyst thickens to several rows of cells. Cyst cavity is not painted. In it is detected parasite (cercariae or metacercariae) - one in each cavity. In the surrounding cyst cells and intercellular substance appears deposition of melanin pigment. At first formed dust-like small granules of reddish color. Eventually granule size increases and they become brown. Later deposition of melanin become black and significantly increases in its size. During the histological examination in perch and roach in addition to the presence of hepatopancreas was firstly established the existence of the pancreas: in perch – near pyloric appendages of the stomach, while roach – along the entire intestine. Also found that every bone of fins perch and roach is presented with lamellar bone, that forms two laterally located bony arcs that cranial and caudal separated by a gap, and generally form the bone structure of oval form. Kidney in perch and roach performs not only its specific function, but also is an organ of lymphopoiesis. In the spleen of perch and roach found a small amount of morphological formations similar to Hassall's corpuscles in the thymus of mammals.