Changes in the cellular composition of the spleen and pronephros of carp Cyprinus carpio infected with the blood fluke Sanguinicola inermis Trematoda: Sanguimcolidae)

Abstract

Ultrastructural changes in cells of carp Cyprinus carpio (L.) spleen and pronephros were studied after experimentally infecting each fish with 500 Sanguinicola inermis cercariae. Cells were identified morphologically and counted within transmission electron microscope preparations of tissues from carp killed 5 and 9 wk post-infection. Results were compared with cell counts in uninfected controls. In the spleen, parasitism induced significant reductions of erythrocytes (p < 0.001), neutrophils (p < 0.01) and eosinophils (p < 0.001) and significant increases of thrombocytes (p < 0.001) and macrophages (p < 0.001). In the pronephros, following infection, there were significant reductions of erythrocytes (p < 0.05), lymphocytes (p < 0.05), thrombocytes (p < 0.05) and eosinophils (p < 0.001) and significant increases of macrophages (p < 0.001) and neutrophils (p < 0.001). These changes are believed to be associated with the presence of adult S. inermis in the host vascular system and/or eggs which become entrapped in host tissues.