In order to observe the growth and development of Fibricola seoulensis metacercariae, the tadpoles of Rana nigromagulata were experimentally infected with the cercariae. The metacercariae of various developmental stages were recovered from the tadpoles after 2 to 65 days of infection. They were prepared for morphological observation, and were given orally to mice to observe their infectivity. The following results were obtained. All of the tadpoles exposed to the cercariae were observed to harbour the larvae in their abdominal cavity. The young metacercariae of 2 days after infection were 121.1 micrometer long and 63.3 micrometer wide. They grow linearly for the first 14 days to be 262.0 micrometer long and 166.4 micrometer wide. Thereafter, no more growth recognized until 65 days. The larvae of 2 days old were similar with cercarial body and had 2 suckers, a pharynx, two ceca and a primordium of germ cells but no tribocytic organ. On the 8th day, they had tribocytic organ, and their morphology resembled that of mature metacercariae. The metacercariae younger than 10 days could not infect the mice. Only the metacercariae older than 14 days had infectivity. The recovery rate increased by the age of metacercariae from 19.0% in 14 days old to 70.0% in 40 days old. Above findings indicate that the tadpole is indispensible for metacercarial development and it needs at least 2 weeks for maturation. The tadpole is a pivotal host in the life cycle of F. seoulensis for connection between the snail and the frog.
parasitology-helminth-trematoda ; Fibricola seoulensis ; metacercaria ; development

A case of gastric anisakiasis due to the larva of Pseudoterranova decipiences was con- firmed by a gastroendoscopic examination. A long whitish nematode larva invading the stomach wall (fundus) was discovered and was extracted using biopsy forceps after 3 days to the onset of symptoms. The worm was 42.6 X 1.1 mm size, and was identified as being a the 4th stage larva of P. decipiens, based upon its morphological characteristics, The patient, residing in Seoul, was a 51-year-old housewife, who complained of severe epi- gastric pain and recalled that she had previously eaten the raw flesh of an Astroconger myriaster in a Japanese restaurant (sushi Bar). This study probably emerges as the 7th human case of gastric anisakiasis of pseudoterranoviasis in Korea.
Anisakiasis ; Asian Continental Ancestry Group ; Biopsy ; Humans* ; Korea ; Larva* ; Middle Aged ; Restaurants ; Seoul ; Stomach ; Surgical Instruments