Pathomorphological changes in Aterina atherina boyeri liver under invasion of Contracaecum rudolphii L. Hartwich, 1964 (Nematoda: Anisakidae)

Parasitological examination of Black Sea aterina ( Atherina boyeri ) has been held in two districts of the Black Sea, Crimean seashore. Fish liver infected by larvae of Contracaecum rudolphii l. has been studied with classical histology and microscopy, the comparative analysis of the obtained data has been carried out with materials of invasion free individuals. It has been observed that pathomorphological changes occur in the aterine liver under C. rudolphii l. parasitizing. Particularly, the parenchyma destruction, tissue dystrophy, microcirculation disorders have been registered. It has been found that the most pronounced changes are recorded in the liver because of severe infestation of nematodes from the aterina ( A. boyeri ): the organ is significantly increased, the edges are rounded, tuberous surface, coloring is light, uneven; the cut liver obtains visible mosaic pattern due to moves done by the larvae of the nematode C. rudolphii l. in the liver parenchyma. Microscopy of histological sections in cases of invasions in the liver parenchyma shows signs of acute congestive hyperemia: central veins and capillaries lobules located closer to them are full of blood and expanded. Hepatocytes in the center of the lobules because of compression of dilated capillaries are subjected to atrophy. In bile ducts acute catarrh accompanied by focal hyperplasia of the epithelial cells is observed; in the aperture of the bile ducts accumulation of mucus with a mixture of desquamated epithelial cells and macrophages is seen.