태화강 유역 담수어와 반함수어에 있어서 흡충류 피낭유충 기생상

Abstract

A study of infestation pattern for larval trematodes from fresh-water fish and brackish-water fish caught at River Taewha was carried out during the period from April to October in 1984.

They were dissected into the flesh, scales and fins with tail, and then examined for the presence and infestation density of larval trematodes.

Of the 11 kinds of fresh-water fish and 3 species of brackish-water fish, the encysted larvae of 7 kinds and undetermined larvae were found in present study. The infestation rates for the larvae varied appreciably from fish to fish. In the intensity of infestation with the metacercaria of Clonorchis sinensis, the Korean shiner, Gnathopogon atromaculatus, was most heavily infected and the mean number of larvae per gram of flesh was 67.0.

The southern topmouthed minnow, Pseudorasbora parva, and the striped shiner, Pungtungia herzi, were intermediately. Their average number varied from 11.7 to 21.4,

The intensity of infestation with the Metagonimus larvae in 9 kinds of fresh-water fish was relatively low, and the average number per gram of flesh varied from 1.0 to 5.0.

In comparison, the brackish-water fish were more heavily infected and the mean number of cysts per gram of flesh in the sweetfish, Plecoglossus altivelis, was 86.4, and the sea-run dace, Tribolodon kakonensis, 10.1.

The findings indicate that the encysted larvae of ClonorcMs sinensis and Metagonimus yokoga-wai from fresh-water fish and brackish-water fish caugt at the River Taewha were heavily infected. Therefore, the infections of the flukes among the residents would be avoided by eating only throughly cooked fish.