[Morphological observation of Haplorchis pumilio]

To provide the basis for the differentiation with similar species of intestinal flukes through observing the figure of Haplorchis pumilio.

Adults of H. pumilio were collected from the intestine of the cat which was infected with the encysted cercariae of H. pumilio for 45 days. The worms were observed after staining. Eggs and metacercariae of H. pumilio were collected and examined for their shape, size and morphological characteristics. Pseudorasbora parva, the fish host, was examined for the parasitized sites of metacercariae.

The principal characteristics of the adults is the acetabulum degradation. There are only the genital sucker with 44-48 hamuli. The average measurement of eggs is 31.2 x 16.7 microns with a smooth shell. Its aceromion is not evident. The average diameter of metacercariae is 168.5 microns. There are squamous spines on metacercaria. The metacercariae only parasitize in the muscle between the basis of the fin and the fish body. The average measurement of metacercaria cyst is 445 x 95 microns, with squamous spines on the body surface. Hamuli are found on the genital sucker of metacercaria cyst.

The morphological figures and parasitic sites of metacercaria, the genital sucker of the adult, and the number and form of the hamulus on the genital sucker provide basis for distinguishing H. pumilio from other intestinal flukes.