In recent years, several marine heterotrophic nanoflagellates have been reported to feed on diatoms much larger than themselves. However, very little is known about the grazer-prey relationships between heterotrophic nanoflagellates and diatoms in aquatic ecosystems. A diatom-feeding flagellate was discovered in the bottom sediment of OnagawaBay. It fed and proliferated on diatoms, especially Skeletonema costatum sensu lato. This study determined growth and ingestion rates of the flagellate on Skeletonema costatum s.l. under laboratory conditons. Its grazing pressure on the sinking flux of S. costatum s.l. was calculated by combining field data. Specific growth rate of the flagellate increased with increasing prey concentration. The maximum specific growth rate was 0.79 d–1 and maximum ingestion rate of the flagellate was 0.66 ng·C·grazer–1·d–1. Calculated grazing pressure of the flagellate on S. costatum s.l. flux was up to 25.6%. The results imply that the flagellate has a considerable grazing impact on S. costatum s.l. flux at least in a restricted season of the year. Therefore, the present study suggests that this benthic flagellate plays an important role in pelagic-benthic coupling inOnagawaBay.
Cite this paper
H. Ohno, Y. Endo, W. Sato-Okoshi and G. Nishitani, "Feeding and Growth Characteristics of a Diatom-Feeding Flagellate Isolated from the Bottom Sediment of Onagawa Bay, Northeastern Japan," Open Journal of Marine Science, Vol. 3 No. 2, 2013, pp. 9-14. doi: 10.4236/ojms.2013.32A002.
 E. B. Sherr, B. F. Sherr and J. McDaniel, “Clearance Rates of <6 μm Fluorescently Labeled Algae (FLA) by Estuarine Protozoa: Potential Grazing Impact of Flagellates and Ciliates,” Marine Ecology Progress Series, Vol. 69, 1991, pp. 81-92. doi:10.3354/meps069081
 E. B. Sherr and B. F. Sherr, “Capacity of Herbivorous Protists to Control Initiation and Development of Mass Phytoplankton Blooms,” Aquatic Microbial Ecology, Vol. 57, No. 3, 2009, pp. 253-262. doi:10.3354/ame01358
 E. B. Sherr and B. F. Sherr, “Heterotrophic Dinoflagellates: A Significant Component of Microzooplankton Biomass and Major Grazers of Diatoms in the Sea,” Marine Ecology Progress Series, Vol. 352, 2007, pp. 187197. doi:10.3354/meps07161
 G. Drebes, S. F. Kühn, A. Gmelch and E. Schnepf, “Cryothecomonas aestivalis sp. nov., a Colourless Nanoflagellate Feeding on the Marine centric diatom Guinardia delicatula (Cleve) Hasle,” Helgolander Meeresunters, Vol. 50, No. 4, 1996, pp. 497-515.
 S. Kühn, L. Medlin and G. Eller, “Phylogenetic Position of the Parasitoid Nanoflagellate Pirsonia Inferred from Nuclear-Encoded Small Subunit Ribosomal DNA and Description of Pseudopirsonia n. gen. and Pseudopirsonia mucosa (Drebes) comb. nov.,” Protist, Vol. 155, No. 2, 2004, pp. 143-156.
 E. Schnepf and S. F. Kühn, “Food Uptake and Fine Structure of Cryothecomonas longipes spec. nov., a Marine Nanoflagellate Incertae Sedis Feeding Phagotrophically on Large Diatoms,” Helgoland Marine Reserach, Vol. 54, No. 1, 2000, pp. 18-32. doi:10.1007/s101520050032
 A. Ishikawa and A. Taniguchi, “Vegetative Cell and Cyst Assemblages of Armored Dinoflagellates in Onagawa Bay, Northeast Japan,” Plankton Biology and Ecology, Vol. 47, No. 1, 2000, pp. 12-22.
 S. Nakamura, “Seasonal Change and Sinking of Diatom Community in Onagawa Bay,” Master Thesis, Tohoku University, Sendai, 2007.
 Y. Masuda, “Pelagic and Benthic Microbial Food Webs in Onagawa Bay,” Ph. D Thesis, Tohoku University, Sendai, 2008.
 P. J. Harrison, R. E. Waters and F. J. R. Taylor, “A Broad Spectrum Artificial Seawater Medium for Coastal and Open Ocean Phytoplankton,” Journal of Phycology, Vol. 16, No. 1, 1980, pp. 28-35.
 B. W. Frost, “Effects of Size and Concentration of Food Particles on the Feeding Behavior of the Marine Planktonic Copepod Calanus pacificus,” Limnology and Oceanography, Vol. 17, No. 6, 1972, pp. 805-815.
 H. Miyai, K. Matsuzaki, K. Ogawa and T. Sugihara, “A Simple Method for the Estimation of Phytoplankton Biomass Based on Cell Morphology,” Bulletin of Plankton Society of Japan, Vol. 35, 1988, pp. 121-126.
 R. R. Strathmann, “Estimating the Organic Carbon Content of Phytoplankton from Cell Volume or Plasma Volume,” Limnology and Oceanorgraphy, Vol. 12, No. 3, 1967, pp. 411-418. doi:10.4319/lo.1967.12.3.0411
 S. Menden-Deuer and E. J. Lessard, “Carbon to Volume Relationships for Dinoflagellates, Diatoms, and other Protist Plankton,” Limnology and Oceanography, Vol. 45, No. 3, 2000, pp. 569-579. doi:10.4319/lo.2000.45.3.0569
 D. Dietrich and H. Arndt, “Biomass Partitioning of Benthic Microbes in a Baltic Inlet: Relationships between Bacteria, Algae, Heterotrophic Flagellates and Ciliates,” Marine Ecology, Vol. 136, No. 2, 2000, pp. 309-322.
 H. J. Jeong, Y. D. Yoo, S. T. Kim and N. S. Kang, “Feeding by the Heterotrophic Dinoflagellate Protoperidinium bipes on the Diatom Skeletonema costatum,” Aquatic Microbial Ecology, Vol. 36, 2004, pp. 171-179.
 R. G. Mattison, H. Taki and S. Harayama, “The Soil Flagellate Heteromita globosa Accelerates Bacterial Degradation of Alkylbenzenes through Grazing and Acetate Excretion in Batch Culture,” Microbial Ecology, Vol. 49, No. 1, 2005, pp. 142-150.
 Y. Yamakawa, “Morphology and Feeding Characteristics of a Diatom-Feeding Flagellate Isolated from the Water Column of Onagawa Bay,” Master Thesis, Tohoku University, Sendai, 2010.
 Y. D. Yoo, H. J. Jeong, M. S. Kim, N. S. Kang, J. Y. Song, W. Shin, K. Y. Kim and K. Lee, “Feeding by Phototrophic Red-Tide Dinoflagellates on the Ubiquitous Marine Diatom Skeletonema costatum,” Journal of Eukaryotic Microbiology, Vol. 56, No. 5, 2009, pp. 413-420.
 S. Menden-Deuer, E. J. Lessard, J. Satterberg and D. Grünbaum, “Growth Rates and Starvation Survival of Three Species of the Pallium-Feeding, Thecate Dinoflagellate Genus Protoperidinium,” Aquatic Microbial Ecology, Vol. 41, No. 2, 2005, pp. 145-152.
 B. Chen, H. Liu and M. T. S. Lau, “Grazing and Growth Responses of a Marine Oligotrichous Ciliate Fed with Two Nanoplankton: Does Food Quality Matter for Micrograzers?” Aquatic Ecology, Vol. 44, No. 1, 2010, pp. 113-119. doi:10.1007/s10452-009-9264-5
 E. J. Burskey, C. J. Coulter and S. L. Brown, “Feeding, Growth and Bioluminescence of the Heterotrophic Dinoflagellate Protoperidinium huberi,” Marine Biology, Vol. 121, 1994, pp. 373-380. doi:10.1007/BF00346747
 J. W. Choi and F. Peters, “Effects of Temperature on Two Psychrophilic Ecotypes of a Heterotrophic Nanoflagellate, Paraphysomonas imperforata,” Applied and Environmental Microbiology, Vol. 58, No. 2, 1992, pp. 593-599.
 J. Laybourn-Parry, “A Functional Biology of Free-Living Protozoa,” University of California Press, California, 1984.
 S. Itakura, I. Imai and K. Itoh, “Morphology and Rejuvenation of Skeletonema costatum (Bacillariophyceae) Resting Cells from the Bottom Sediments of Hiroshima Bay, the Seto Inland Sea, Japan,” Bulletin of Plankton Society of Japan, Vol. 38, No. 2, 1992, pp. 135-145.