Abstract

In order to know relationship between the clavate cells of epidermis and infectivity of metacercariae of C. sinensis. histological investigation of epidermis was carried out on the 26 species of fresh-water fish collected from the main rivers in Korea. Results were summarized as it follows: In general clavate cell had a single nucleus at its center. However it was observed in Liobagrus mediadiposalis and Pelteobagrus fuluidraco that clavate cell had two nuclei with and independent so-called light halo of Oxner and in some cases had none of them. In following species; Misgurnus anguillicaudatus, Cobitis taenia, Liobagrus mediadiposalis, Pelteobagrus fuluidraco, Parasilurus asotus and Anguilla japonica, scales were not detected or buried in the dermis layer, and the epidermis was mostly consisted of clavate cells. Among these species, it was observed that no metacercariae were found. In case of Cyprinus carpio, Carassius carassius (crusian carp and golden crusian carp), Sarcocheilichthys czerskii, Pungtungia herzi and Coreoleuciscus splendius, scales were exposed over the epidermis, in which clavate cells were abundantly found. In these species, a few of the metacercariae were detected. On the other hand, no clavate cells were observed in Pseudorasbora parva , Zacco platypus, Microphysogobio koreensis, Gnathopogon majimae, Gnathopogon coreanus, Acheilognathus signifer, Acheilognathus yamatsutae, Cultriculus eigenmanni, Coreoperca herzi, Pseudoperilampus uyekii, Pseudoperilampus notatus and Pseudogobio esocinus. These fishes with exposed scales on the epidermis were well known to serve as the second intermediate hosts of C. sinensis. From the above results obtained, it was suggested that the existance of clavate cells in the epidermis of the fresh-water fish seems to be correlated with the infectivity of the metacercariae of C. sinensis.