0065-1583 Jagiellonian University in Kraków Notes on the Occurrence of Tintinnid Ciliates, and the Nasselarian Radiolarian Amphimelissa setosa of the Marine Microzooplankton, in the Chukchi Sea (Arctic Ocean) Sampled each August from 2011 to 2020 Dolan John R. author Moon Jong-Kuk author Yang Eun Jin author Laboratoire d’Océanographie de Villefranche-sur-Mer, CNRS-Sorbonne Université UMR7093, Institut de la Mer de Villefranche, IMEV, Station Zoologique Korea Polar Research Institute, KIOST, 213-3 Songdo-dong, Yeonsu-gu, Incheon, 406-840, Korea Correspondence to: John R. Dolan john.dolan@imev-mer.fr Correspondence to: Jong-Kuk Moon Correspondence to: Eun Jin Yang 05 08 2021 Volume 60 2021 1 11 Copyright © 2021 2021 <p>Here we summarize the results from 10 cruises in the Chukchi Sea, in August, each year from 2011 to 2020. Samples for the qualitative analysis of the microzooplankton were obtained from stations located across the Chukchi Sea using a 20μm plankton net. Conditions encountered, in terms of sea ice coverage and chlorophyll concentrations, varied widely from year to year without any obvious relationship with the composition of the microzooplankton assemblage. Examining a total of 242 samples gathered, we found a total of 44 tintinnid species (morphologically distinct forms). Plotting cumulative number of tintinnid species encountered vs cumulative number of samplings gave a typical species accumulation curve showing no sign of saturation suggesting that continued sampling in the Chukchi Sea will likely yield increases in the tintinnid species catalogue. The tintinnid species found ranged widely in lorica opening diameters (LOD) from about 11 μm to 80 μm in diameter. However, the median size of the LOD of the tintinnid assemblages varied little from year to year ranging only from about 30 μm to 40 μm. Most of the forms encountered were found in samples from only 1 or 2 cruises. Very few forms were found every year throughout the 10 years of sampling. These were 5 species of tintinnids (Acanthostomella norvegica, Leprotintinnus pellucidus, Pytchocylis obtusa, Salpingella acuminata, Salpingella faurei) and the nasselarian radiolarian Amphimelissa setosa. Examples of the morphological variability observed among individuals of Acanthostomella norvegica and Pytchocylis obtusa within single samples are shown with some individuals easily confused with forms described as other species are shown. To our knowledge, our data are the most extensive data set on Chukchi Sea microplankton. We provide all of the data recorded, which may serve as a baseline from which to assess changes projected in Arctic Sea systems, in a supplementary data file.</p> 1 Abe Y., Matsuno K., Fujiwara A., Yamaguchi A. (2020) Review of spatial and inter-annual changes in the zooplankton community structure in the western Arctic Ocean during summers of 2008–2017. Prog. Oceanogr. 186: 102–391 2 Agatha S. and Reidel-Lorjé J.C. (2006) Redescription of Tintinnopsis cylindrica Daday, 1887 (Ciliophora: Spirotricha) and unification of tintinnid terminology. Acta Protozool., 45: 137–151 3 Amano K., Abe Y., Matsuno K., Yamaguchi A. (2019) Yearly comparison of the planktonic chaetognath community in the Chukchi Sea in the summers of 1991 and 2007. Pol. Sci. 19: 112–119 4 Arrigo K. R., van Dijken G. L. (2015) Continued increases in Arctic Ocean primary production. Prog. Oceanogr. 136: 60–70 5 Baker M. R., Kivva K. K., Pisareva M. N., Watson J. T., Selivanova J. (2020) Shifts in the physical environment in the Pacific Arctic and implications for ecological timing and conditions. Deep Sea Res. Part II 177: 104–802 6 Bursa A. (1963) Phytoplankton in coastal waters of the Arctic Ocean at Point Barrow Alaska. Arctic 16: 239–262 7 Connell P. E., Michel C., Meisterhans G., Arrigo K. R., Caron D. A. (2018) Phytoplankton and bacterial dynamics on the Chukchi Sea Shelf during the spring-summer transition. Mar. Ecol. Prog. Ser. 602: 49–62 8 Danielson S. L., Ahkinga O., Ashjian C., Basyuk E., Cooper L. W., Eisner L., Farley E., Iken K. B., Grebmeier J. M., Juranek L., Khen G., Jayne S. R., Kikuchi T., Ladd C., Lu K., McCabe R. M., Moore G. W. K., Nishino S., Ozenna F., Pickart R. S., Ployakov I., Stabeno P. J., Thoman R., Williams W. J., Wood K., Weingartner T. J. (2020) Manifestation and consequences of warming and altered heat fluxes over the Bering and Chukchi Sea continental shelves. Deep Sea Res. Part II 177: 104–781 9 Davis C. C. (1981) Variations of lorica shape in the genus Ptychocylis (Protozoa: Tintinnina) in relation to species identification. J. Plankton Res. 3: 433–443 10 Davis C. C. (1985) Acanthostomella norvegica (Daday) in Insular Newfoundland waters, Canada (Protozoa: Tintinnina). Int. Rev. Ges. Hydrobiol. 70: 21–26 11 Dolan J. R. (2010) Morphology and ecology in tintinnid ciliates of the marine plankton: correlates of lorica dimensions. Acta Protozool. 49: 235–244 12 Dolan J. R., Yang E. J. (2017) Observations of apparent lorica variability in Salpingacantha (Ciliophora: Tintinnida) in the Northern Pacific and Arctic Oceans. Acta Protozool. 56: 217–220 13 Dolan J. R., Yang E. J., Kim T. W., Kang S. H. (2014) Microzooplankton in a Warming Arctic: A Comparison of Tintinnids and Radiolarians from Summer 2011 and 2012 in the Chukchi Sea. Acta Protozool. 53: 101–113 14 Dolan J. R., Pierce R. W., Yang E. J. (2017). Tintinnid ciliates of the marine microzooplankton in Arctic Seas: a compilation and analysis of species records. Pol. Biol. 40: 1247–1260 15 Hada Y. (1937) The fauna of Akkeshi Bay IV. The pelagic ciliata. J. Fac. Sci. Hokkaido Imperial Univ, Series 6, Zool 5: 147–216 16 Jung J. H., Moon J. H., Park K. M., Kim S., Dolan J. R., Yang E. J. (2018) Novel insights into the genetic diversity of Parafavella based on mitochondrial CO1 sequences. Zool. Scripta, 47: 743–755 17 Kofoid C. A., Campbell A. S. (1929) A Conspectus of the Marine and Freshwater Ciliata Belonging to the suborder Tintinnoinea, with Descriptions of New Species Principally from the Agassiz Expedition to the Eastern Tropical Pacific 1904–1905. Univ. Calif. Publ. Zool. 34: 1–403 18 Kofoid C. A., Campbell A. S. (1939) The Ciliata: The Tintinnoinea. Bull. Mus. Comp. Zool. Harvard 84: 1–473 19 Lee Y., Min J. O., Yang E. J., Cho K. H., Jung J., Park J., Moon J. K., Kang S. H. (2019) Influence of sea ice concentration on phytoplankton community structure in the Chukchi and East Siberian Seas, Pacific Arctic Ocean. Deep Sea Res. Part I 147: 54–64 20 Li H., Xu Z., Zhang W., Wang S., Zhang G., Xiao T (2016) Boreal tintinnid assemblage in the Northwest Pacific and its connection with the Japan Sea in summer 2014. PLoS ONE11: e0153379.doi:10.1371/journal.pone.0153379 21 Matsuno K. (2014) Spatial and temporal changes in the plankton community in the western Arctic Ocean. Mem. Fac. Fish. Sci., Hokkaido University, 56: 65–107 22 Matsuno K., Ichinomiya M., Yamaguchi A., Imai I., Kikuchi T. (2014) Horizontal distribution of microprotist community structure in the western Arctic Ocean during late summer and early fall of 2010. Pol. Biol. 37: 1185–1195 23 Neeley A. R., Harris L. A., Frey K. E. (2018) Unraveling phytoplankton community dynamics in the northern Chukchi Sea under sea-ice-covered and sea-ice-free conditions. Geophys. Res. Lett. 45: 7663–7671 24 Spear A., Duffy-Anderson J., Kimmel D., Napp J., Randall J., Stabeno P. (2019) Physical and biological drivers of zooplankton communities in the Chukchi Sea. Pol. Biol. 42: 1107–1124 25 Zhang W., Feng M., Yu Y., Zhang C., Xiao T. (2019) Vertical distribution of oceanic tintinnid (Ciliophora: Tintinnida) assemblages from the Bering Sea to Arctic Ocean through Bering Strait. Pol. Biol., 42: 2105–2117 26 Wang C., Li H., Xu Z., Zheng S., Hao Q., Dong Y., Zhao L., Zhang W., Zhao Y., Grégori G., Xiao T. (2020) Difference of planktonic ciliate communities of the tropical West Pacific, the Bering Sea and the Arctic Ocean. Acta Oceanol. Sin., 39: 9–17 27 Wang Y., Kang J., Xiang P., Wang W., Lin M. (2020) Short timeframe changes of environmental impacts on summer phytoplankton in the Chukchi Sea and surrounding areas in a regional caling. Ecological Indicators 117: 106693 28 Wuchang Z., Meiping F., Ying Y., Cuixia Z., Tian X. (2012) An Illustrated Guide to Contemporary Tintinnids in the World. Beijing: Science Press, 499 pp 29 Xu G., Yang E., Jiang Y., Cho K. H., Jung J., Lee Y., Kang S. H. (2018) Can pelagic ciliates indicate vertical variation in the water quality status of western Arctic pelagic ecosystems? Mar. Poll. Bull. 133: 182–190 30 Yang E. J., Ha H. K., Kang S. H. (2015) Microzooplankton community structure and grazing impact on major phytoplankton in the Chukchi sea and the western Canada basin, Arctic ocean. Deep Sea Res. Part II 120: 91–102 31 Yokoi N., Matsuno K., Ichinomiya M., Yamaguchi A., Nishino S., Onodera J., Inoue J., Kikuchi T. (2016). Short-term changes in a microplankton community in the Chukchi Sea during autumn: consequences of a strong wind event. Biogeosciences, 13: 913–923