Ocean and Polar Research

Korea Institute of Ocean Science & Technology (한국해양과학기술원)
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Pathology Survey of the Manila Clam Ruditapes philippinarum from Hwangdo Tidal Flat in Cheonsu Bay on the West Coast of Korea

  • Yang, Hyun-Sung (Department of Marine Life Science and Marine Science Institue (BK21 FOUR), Jeju National University) ;
  • Cho, Young-Ghan (Department of Marine Life Science and Marine Science Institue (BK21 FOUR), Jeju National University) ;
  • Shin, Jong-Seop (Department of Marine Life Science and Marine Science Institue (BK21 FOUR), Jeju National University) ;
  • Park, Heung-Sik (Research Project Development Department, Korea Institute of Ocean Science & Technology) ;
  • Choi, Kwang-Sik (Department of Marine Life Science and Marine Science Institue (BK21 FOUR), Jeju National University)
  • Received : 2021.11.08
  • Accepted : 2021.12.01
  • Published : 2021.12.30
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Abstract

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.

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Acknowledgement

We are grateful to the Shellfish Aquaculture and Research Laboratory of Jeju National University staff for their help in sampling and histology preparation. This study was supported by the research grant of Jeju National University in 2021. These authors (Yang HS, Cho YG) contributed equally.

References

  1. Cho YG, Kang HS, Le CT, Kwon MK, Jang MS, Choi KS (2020) Molecular characterization of Urosporidium tapetis sp. nov., a haplosoridian hyperparasite infecting metacercaria of Parvatrema duboisi (Dollfus 1923), a trematode parasite of Manila clam Ruditapes philippinarum on the west coast of Korea. J Invetebr Pathol 175(2020):107454 https://doi.org/10.1016/j.jip.2020.107454
  2. Choi JK, Oh HJ, Koo BJ, Lee S, Ryu JH (2011) Macrobenthos habitat mapping in a tidal flat using remotely sensed data and a GIS-based probabilistic model. Mar Pollut Bull 62:564-572 https://doi.org/10.1016/j.marpolbul.2010.11.028
  3. Choi KS Powell EN, Lewis DH, Ray SM (1994) Instantaneous reproductive effort in female American oysters, Crassostrea virginica, measured by a new immunoprecipitation assay. Biol Bull 186:41-61 https://doi.org/10.2307/1542035
  4. Choi KS Wilson EA, Lewis DH, Powell EN, Ray SM (1989) The energetic cost of Perkinsus marinus parasitism in oysters: quantification of the thioglycollate method. J Shellfish Res 8:125-131
  5. Lee HM, Cho YG, Jeung HD, Jang MS, Hwang JY, Choi KS (2020a) Are juvenile Manila clam Ruditapes philippinarum free from Perkinsus olseni infection in Korean waters?. Ocean Sci J 55:573-579 https://doi.org/10.1007/s12601-020-0038-2
  6. Lee HM, Kim HJ, Park KI, Choi KS (2020b) Enhanced growth, gonad maturation, and low-level parasite infection in juvenile Manila clam Ruditapes philippinarum cultured in subtidal cages on the south coast of Korea. Aquaculture 526:735410. doi:10.1016/j.aquaculture.2020.735410
  7. Lee HM, Park KI, Yang HS, Choi KS (2021) Negative impacts of Perkinsus olseni infection in Manila clam Ruditape philippinarum observed from tidal flats in Anmyeondo Island on the west coast of Korea during the post-spawning period. Ocean Sci J 56:307-316 https://doi.org/10.1007/s12601-021-00024-0
  8. Nam KW, Jeung HD, Song JH, Park KH, Choi KS, Park KI (2018) High parasite bu rden increases the su rfacing and mortality of the manila clam (Ruditapes philippinarum) in sandy intertidal mudflats on the west coast of Korea during hot summer. Parasite Vector 11:42. doi:10.1186/s13071-018-2620-3
  9. Park KI, Choi KS (2001) Spatial distribution of the protozoan parasite, Perkinsus sp., found in the manila clam, Ruditapes philippinarum in Korea. Aquaculture 203:9-22 https://doi.org/10.1016/S0044-8486(01)00619-6
  10. Park KI, Figueras A, Choi KS (2006) Application of Enzyme-Linked Immunosorbent Assay (ELISA) for the study of reproduction in the Manila clam Ruditapes philippinarum (Mollusca: Bivalvia): II. Impacts of Perkinsus olseni on clam reproduction. Aquaculture 251:182-191 https://doi.org/10.1016/j.aquaculture.2005.06.003
  11. Park KI, Park JK, Lee J, Choi KS (2005) Use of molecular markers for species identification of Korean Perkinsus sp. isolated from Manila clams Ruditapes philippinarum. Dis Aquat Org 66:255-263 https://doi.org/10.3354/dao066255
  12. Park KI, Tsutusmi H, Hong JS, Choi KS (2008) Pathology survey of the short-neck clam Ruditapes philippinarum on sandy tidal flats along the coast of Ariake Bay, Kyushu, Japan. J Invertebr Pathol 99:212-219 https://doi.org/10.1016/j.jip.2008.06.004
  13. Park KJ, Song JH, Choi YS, An KH (2013) Changes in density and culture conditions of the Manila clam Ruditapes philippinarum on the west coast of Korea. Korean J Malacol 29:207-216 https://doi.org/10.9710/kjm.2013.29.3.207
  14. Ray SM (1966) A review of the culture method for detecting Dermocystidium marinum with suggested modifications and precautions. Proc Natl Shellfish Ass 54:55-69
  15. Uddin MJ, Yang HS, Choi KS Kim HJ, Hong JS, Cho M (2010) Seasonal changes in Perkinsus olseni infection and gametogenesis in Manila clam, Ruditapes philippinarum, from Seonjedo Island in Incheon, off the west coast of Korea. J World Aquacult Soc 41:93-101 https://doi.org/10.1111/j.1749-7345.2009.00337.x
  16. Uddin MJ, Yang HS, Park KJ, Kang CK, Kang HS, Choi KS (2012) Annual reproductive cycle and reproductive efforts of the Manila clam Ruditapes philippinarum in Incheon Bay off the west coast of Korea using a histology-ELISA combined assay. Aquaculture 364-365:5-32
  17. Villalba A, Reece KS, Ordas MC, Casas SM, Figueras A (2004) Perkinsosis in molluscs: a review. Aquat Living Resour 17:411-432 https://doi.org/10.1051/alr:2004050
  18. Waki T, Takahashi M, Eki T, Hiasa M, Umeda K, Karakawa N, Yoshinaga T (2018) Impact of Perkinsus olseni infection on a wild population of Manila clam Ruditapes philippinarum in Ariake Bay, Japan. J Invertebr Pathol 15:134-144
  19. Yang HS, Park KI, Donaghy L, Adhya M, Choi KS (2012) Temporal variation of Perkinsus olseni infection intensity in the Manila clam Ruditapes philippinarum in Gomso Bay, off the west coast of Korea. J Shellfish Res 31:685-690 https://doi.org/10.2983/035.031.0312
  20. Yang HS, Park KJ, Choi KS (2010) Pathologic survey on the Manila Clam Ruditapes philippinarum (Adams and Reeve 1850) from Haeju off the Western Coastal Yellow Sea. Ocean Sci J 45:93-100 https://doi.org/10.1007/s12601-010-0008-1