• Journal of Ecology and Environment
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• v.30 no.1
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• pp.97-99
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• 2007

Waders inhabiting an area in which A. tyosenense is endemic were examined to determine if they serve as reservoir hosts for the parasite. Of the waders examined, 4 individuals from 2 species were found to be hosts for 18 to 1820 adult worms. Common and velvet scoters, which are known to be the final hosts of A. tyosenense, are rare in the infected areas, while waders are prevalent and prey on the bivalves known to be intermediate hosts of A. tyosenense. Thus, from the experimental results and circumstances presented herein, we conclude that waders are definitive and reservoir hosts of A. tyosenense in nature.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.05a
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• pp.427-428
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• 2000

본 연구는 우리 나라 간석지 산 패류에서의 흡충류 분류와 생활사 그리고 패류의 병해를 구명할 목적으로 1999년 3월부터 2000년 3월까지 만경강 하구 역에 위치한 심포 지선 간석지 애서 채집한 갯우렁이(Lunatia fortuni)와 큰구슬우렁이에서 Cercaria yamagutii Ito, 1957 동죽(Mactra veneriformis)과 맛조개 및 바지락에서 Acanthoparyphium tyosen Yamaguti,1939의 피낭유충을 검출하고, 이를 실험실에서 감염실험을 실시한 바, 지금까지 Yamaguti(1939) 와 Ito(1956), 김 등(1984, 1988)이 밝히지 못한 Acanthoparyphium tyosene의 전 생활사가 밝혀졌기에 보고한다. (중략)

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.6
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• pp.720-728
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• 2001

Cercaria yamagutii Ito, 1957 (C. yamagutii) was found in Lunatia fortuni (L. fortuni) and Neverita didyma (N. didyma) collected from the tideland of Sim-po located at the estuary of the Mankyong River, Chonbuk. It was finally confirmed that the parasite is Acanthoparyphium tyosenense Yamaguti, 1939 (A. tyosenense) and its life history was clarified in this study. Mactra veneriformis (M. veneriformis) was artificially infected with C. yamagutii isolated from L. fortuni and N. didyma. It began to intrude into M. veneriformis through the inhalent canal. Five hours after infection, the tails of the cercaria began to be separated from the main body and the cercaria started to form cysts. Mature cysts were formed 340 hours (14 days) after infection. The cysts were $300\sim360{\mu}m$ in diameter and the encysted metacercarias were $790\sim800\times300\sim310{\mu}m$ in size. The metacercarias were administered orally to Larus crassiostris (L. crassiostris), and adult worms of $84.5\sim112.5\times55\sim65{\mu}m$ were found full of eggs with $2.20\~3.70$ mm long and $0.40\~0.59$ mm wide after 10 days. In a field study, it was observed that the infection rate of A. tyosenense is $99.5\%$ in M. venerifomis, $76.3\%$ Solen strictus (S. strictus), and $37\%$ Ruditapes philippinarum (R. philippinarum), No difference was found among different host sizes, It was concluded that the first intermediate hosts of A. tyosenense Yamaguti were L. fortuni, N. didyma, Tympanotonus microptera, Cerithidea (Cerithidea) largillierti, Cerithidea (Cerideopsilloa) cingulata, the second intermediate hosts M. venerifomis, S. strictus and R. philippinamn, and the final hosts L. crassiostris and Melanitta fusca stejnegeri.

• Parasites, Hosts and Diseases
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• v.59 no.4
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• pp.341-353
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• 2021

Acanthoparyphium shinanense n. sp. (Digenea: Echinostomatidae) is described from chicks experimentally infected with the metacercariae encysted in 2 brackish water clam species, Ruditapes philippinarum and Coecella chinensis, in the Republic of Korea. The metacercariae were round to oval, armed with 23 collar spines, and 0.216 (0.203-0.226) mm in diameter. From 5 chicks experimentally infected each with 200 metacercariae, 34 juvenile (5-day-old worms) and 104 adult flukes (7-day-old worms) were harvested from their small intestines, with the average worm recovery rate of 13.8%. The adult flukes were 3.18 (2.89-3.55) mm long and 0.68 (0.61-0.85) mm wide, with an elongated, posteriorly tapering body, and a prominent head collar armed with 23 collar spines arranged in a single uninterrupted row. The posterior testis of A. shinanense was longitudinally elongated, which is similar to Acanthoparyphium spinulosum Johnston, 1917 but unique from the other closely related species, including Acanthoparyphium tyosenense Yamaguti, 1939, Acanthoparyphium kurogamo Yamaguti, 1939, and Acanthoparyphium marilae Yamaguti, 1934. The eggs of A. shinanense were larger than those of A. spinulosum, and the anterior extent of 2 lateral groups of vitellaria was slightly more limited in A. shinanense than in A. spinulosum. Molecular analysis of nuclear and mitochondrial genes revealed low homology with A. spinulosum from USA (96.1% in 5.8S rRNA) and Ukraine (97.9% in 28S rRNA), Acanthoparyphium n. sp. from USA (98.0% in 28S rRNA), and Acanthoparyphium sp. from Australia, Kuwait, and New Zealand. Biological characteristics, including its first intermediate host and natural definitive hosts, as well as its zoonotic capability, should be elucidated.

• Parasites, Hosts and Diseases
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• v.46 no.2
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• pp.101-104
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• 2008

Metacercariae of Acanthoparyphium marilae Yamaguti, 1934 (Digenea: Echinostomatidae) were discovered in an intertidal clam, Mactra veneriformis, in a southwestern coastal area of the Republic of Korea. A total of 128 metacercariae were detected from 10 clams examined. They were round, 320 m in average diameter, with 23 collar spines. They were fed experimentally to chicks, and 10 days later adult flukes were obtained. The adults were morphologically characterized by the head collar with a single row of 23 dorsally uninterrupted spines, without special end group spines, a round ventral sucker, 2 round and tandem testes, and vitellaria extending at lateral fields from the posterior extremity not beyond the middle level of the posterior testis. The most characteristic feature of this species was the limited distribution of vitellaria, which differs from Acanthoparyphium tyosenense Yamaguti, 1939, the metacercariae of which are encysted in the same mollusk species. This is the first report in which the metacercariae of this species were detected, and the intertidal bivalve, M. veneriformis, has been identified as a second intermediate host for A. marilae.

• Parasites, Hosts and Diseases
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• v.55 no.4
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• pp.399-408
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• 2017

A survey was performed to know the recent infection status of digenetic trematode metacercariae in clams and oysters from 4 sites in western coastal regions of the Republic of Korea (=Korea). Four species of clams (Mactra veneriformis, Ruditapes philippinarum, Cyclina sinensis, and Saxidomus purpuratus) were collected from Taean-gun, Chungcheongnam-do (Province), Buan-gun (County) and Gochang-gun, Jeollabuk-do, and oysters, Crassostrea gigas, from Shinan-gun, Jeollanam-do were transferred to our laboratory on ice and examined by the artificial digestion method. The metacercariae of Himasthla alincia were detected in 3 species of clams, M. veneriformis, R. philippinarum, and C. sinensis from the 3 surveyed areas. The positive rate and the mean density per clam infected were 98.9% (30.8 metacercariae) in M. veneriformis, 60.0% (5.0) in R. philippinarum, and 96.0% (28.4) in C. sinensis. The positive rate (mean density) of Acanthoparyphium tyosenense metacercariae in M. veneriformis was 50.0% (2.1) from Taean-gun and 70.0% (2.8) from Gochang-gun. The metacercariae of Parvatrema spp. were detected in M. veneriformis and R. philippinarum from Taean-gun and Gochang-gun; the positive rate (mean density) was 63.3% (4,123) and 50.0% (19) in M. veneriformis, and 6.7% (126) and 100% (238) in R. philippinarum from the 2 regions, respectively. The metacercariae of Gymnophalloides seoi were detected in all 30 oysters from Shinan-gun, and their average density per oyster was 646. From the above results, it has been confirmed that more than 3 species of metacercariae are prevalent in clams from the western coastal regions, and G. seoi metacercariae are still prevalent in oysters from Shinan-gun, Jeollanam-do, Korea.