• Korean Journal of Environmental Biology
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• v.21 no.2
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• pp.177-180
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• 2003

Four genera of metazoan parasites were recovered from 3 of 6 Sebastes pinniger examined during January 2003. Two hundred forty-five metazoan parasites were recovered. Trochopus trituba Sekerak and Arai, 1977 and Anisakis larvae were found to he infected S. finniger Gill and te be abundant in this rockfish. One hundred eleven worms of monogenean trematodes and 134 larval anisakine nematodes were also found in this fishes. Precise positions with regard to gills, fins, and gastrointestinal tracts were recorded on S. pinniger to determine distribution of metazoan parasites of Trochopus trituba, Anisakis simplex larva, Contracaecum sp. larva, and Pseudo terranova decipiens larva. The monogenean trematodes, T. trituba were attacked to the gill arches and fin, and the larval anisakine nematodes, A. simplex, Contracaecum sp.,and P. decipiens were found on the visceral organs such as intestine, omentum and stomach wall. The second gill arches were the most heavily infested and posterodorsal region of the gill arches contained most monegenenn trematodes. The nam site of infestation of larval anisakine nematodes were the intestine.

• Ocean and Polar Research
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• v.43 no.4
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• pp.365-370
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• 2021

Manila clam Ruditapes philippinarum is present at high rates of density in tidal flats in Cheonsu Bay on the west coast of Korea, where clams often exhibit mass mortalities in late summer. We monitored the pathologic condition of clams at Hwangdo tidal flat (HD) to understand the parasitic impacts on clam fitness. Manila clams were fully ripe in July and spawned during August and September, as the histology indicated. The histology revealed that clams in HD tidal flats were heavily infected by the protozoa parasite Perkinsus olseni, as the monthly prevalence ranged from 53% (September) to 93% (August). In addition, Manila clams were co-infected by the metazoan parasite Cercaria tapetis and Parvatrema duboisi with the prevalence of 0-33% and 0-14%, respectively. Massive hemocyte infiltration and subsequent inflammation were commonly observed from the gills of P. olseni infected clams. Clusters of P. olseni trophozoites and heavy hemocyte infiltration were also observed from the female gonad, suggesting that P. olseni interferes with host gonad maturation. The larval trematode occupied almost the entire host gonad, resulting in gonad castration. In addition, Metacercaria of P. duboisi were observed from the subsurface of the mantle. Ray's fluid thioglycollate medium assay (RFTM) indicated that clams collected in August and September contained approximately 4.0×106 P. olseni cells/g gills. Condition Index (CI) declined gradually from spring to early summer, and the decline in CI was interpreted as a consequence of the heavy parasitism, as the parasites drain the host's net energy to be used in somatic growth and gamete production.

• Parasites, Hosts and Diseases
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• v.52 no.2
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• pp.163-168
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• 2014

Wnt proteins are a family of secreted glycoproteins that are evolutionarily conserved and considered to be involved in extensive developmental processes in metazoan organisms. The characterization of wnt genes may improve understanding the parasite's development. In the present study, a wnt4 gene encoding 491amino acids was amplified from cDNA of metacestodes of Taenia solium using reverse transcription PCR (RT-PCR). Bioinformatics tools were used for sequence analysis. The conserved domain of the wnt gene family was predicted. The expression profile of Wnt4 was investigated using real-time PCR. Wnt4 expression was found to be dramatically increased in scolex evaginated cysticerci when compared to invaginated cysticerci. In situ hybridization showed that wnt4 gene was distributed in the posterior end of the worm along the primary body axis in evaginated cysticerci. These findings indicated that wnt4 may take part in the process of cysticerci evagination and play a role in scolex/bladder development of cysticerci of T. solium.