Protoraphis Simonsen, a newly recorded marine epizoic diatom genus for China

  • Lang Li
  • Changping ChenEmail author
  • Lin Sun
  • Jiawei Zhang
  • Junrong Liang
  • Yahui GaoEmail author


Epizoic diatoms on marine copepods are common in nature and may have a special ecological relationship with their hosts. However, this special ecological group is not well known, and it has only rarely been studied in the China seas. To address this knowledge gap, the species diversity and classification of epizoic diatoms on planktonic copepods were studied with samples collected from the East China Sea. In the present study, a marine araphid diatom genus Protoraphis and its type species, Pr. hustedtiana, were observed and identified by light and electron microscopy, thus representing the first record of this genus and its type species in China. This genus is characterized by a median sternum strongly bent to opposite sides and terminate in two transapical grooves at the valve ends. Protoraphis hustedtiana was found to be epizoic on the posterior body appendages and segments of the marine calanoid copepod Candacia bradyi. An internal view shows a complex, ear-shaped process that is close to the apical slit field. The ecological habitats and geographical distributions of Protoraphis were also discussed, and, together with complementary morphological studies, our results have increased the number of records for marine epizoic diatoms to three genera with three species in China, including Pseudohimantidium and Pseudofalcula.

Key words

marine epizoic diatom copepod Protoraphis newly recorded genus ear-shaped process 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.



We thank Caiming Wu and Luming Yao from the Electron Microscopy Laboratory, Xiamen University, for providing assistance with SEM observation. We also thank David Martin for his assistance with language editing.


  1. Ashworth M P, Ruck E C, Lobban C S, et al. 2012. A revision of the genus Cyclophora and description of Astrosyne gen. nov. (Bacillariophyta), two genera with the pyrenoids contained within pseudosepta. Phycologia, 51(6): 684–699, doi: CrossRefGoogle Scholar
  2. Donadel L, Torgan L C. 2016. Falcula hyalina (Fragilariaceae, Bacillariophyta) from a coastal lagoon, Southern Brazil: an additional approach on its morphology. Phytotaxa, 243(2): 185–189, doi: CrossRefGoogle Scholar
  3. Fernandes L F, Calixto-Feres M. 2012. Morphology and distribution of two epizoic diatoms (Bacillariophyta) in Brazil. Acta Botanica Brasilica, 26(4): 836–841, doi: CrossRefGoogle Scholar
  4. Foged N. 1984. Freshwater and littoral diatoms from Cuba. Bibliotheca Diatomologica, 5: 1–243Google Scholar
  5. Frankovich T A, Ashworth M P, Sullivan M J, et al. 2016. Medlinella amphoroidea gen. et sp. nov. (Bacillariophyta) from the neck skin of Loggerhead sea turtles (Caretta caretta). Phytotaxa, 272(2): 101–114, doi: CrossRefGoogle Scholar
  6. Frankovich T A, Ashworth M P, Sullivan M J, et al. 2018. Epizoic and apochlorotic Tursiocola species (Bacillariophyta) from the skin of Florida manatees (Trichechus manatus latirostris). Protist, 169(4): 539–568, doi: CrossRefGoogle Scholar
  7. Frankovich T A, Sullivan M J, Stacy N I. 2015. Tursiocola denysii sp. nov. (Bacillariophyta) from the neck skin of Loggerhead sea turtles (Caretta caretta). Phytotaxa, 234(3): 227–236, doi: CrossRefGoogle Scholar
  8. Gárate-Lizárraga I, Esqueda-Escárcega G M. 2018. Ditrichocorycaeus anglicus (Copepoda; Poecilostomatoida), new basibiont of Pseudohimantidium pacificum (Bacillariophyceae) in Bahía de La Paz, Gulf of California. CICIMAR Oceánides (in Spanish), 33(1): 63–67Google Scholar
  9. Gibson R A. 1979a. Protoraphis atlantica sp. nov., a new marine epizoic diatom. Bacillaria, 2: 109–126Google Scholar
  10. Gibson R A. 1979b. An ultrastructure study of Pseudohimantidium pacificum Hust. & Krasske (Bacillariophyceae: Photoraphidaceae) with special reference to the labiate processes. Nova Hedwigia Beihefte, 64: 147–161Google Scholar
  11. Gómez F, Wang Lu, Lin Senjie. 2018. Morphology and molecular phylogeny of epizoic araphid diatoms on marine zooplankton, including Pseudofalcula hyalina gen. & comb. nov. (Fragilariophyceae, Bacillariophyta). Journal of Phycology, 54(4): 557–570, doi: CrossRefGoogle Scholar
  12. Guiry M D, Guiry G M. 2018. AlgaeBase. World-wide electronic publication, National University of Ireland, Galway. [2003-09-22/2018-07-15]Google Scholar
  13. Hallegraeff G M, McWilliam P S. 1990. The complex labiate process of the epizoic diatom Protoraphis hustedtiana Simonsen. Beihefte zur Nova Hedwigia, 100: 39–45Google Scholar
  14. Hiromi J, Kadota S, Takano H. 1985. Diatom infestation of marine copepods (review). Bulletin of Tokai Regional Fisheries Research Laboratory, 117: 37–45Google Scholar
  15. Jiao Nianzhi, Yang Yanhui, Hong Ning, et al. 2005. Dynamics of autotrophic picoplankton and heterotrophic bacteria in the East China Sea. Continental Shelf Research, 25(10): 1265–1279, doi: CrossRefGoogle Scholar
  16. Li Xuesong, Chen Changping, Liang Junrong, et al. 2014. Morphology and occurrence of a marine epizoic diatom Falcula hyalina Takano (Bacillariophyta) in China. Algological Studies, 145–146: 169–179, doi: Google Scholar
  17. Lobban C S, Ashworth M P. 2014. Lucanicum concatenatum, gen. nov., sp. nov., a benthic marine diatom from Guam, and a less restrictive diagnosis for Cyclophorales (Bacillariophyta). Marine Biodiversity Records, 7: 1–8, doi: CrossRefGoogle Scholar
  18. Majewska R, Kociolek J P, Thomas E W, et al. 2015. Chelonicola and Poulinea, two new gomphonemoid diatom genera (Bacillariophyta) living on marine turtles from Costa Rica. Phytotaxa, 233(3): 236–250, doi: CrossRefGoogle Scholar
  19. Majewska R, Van de Vijver B, Nasrolahi A, et al. 2017. Shared epizoic taxa and differences in diatom community structure between green turtles (Chelonia mydas) from distant habitats. Microbial Ecology, 74(4): 969–978, doi: CrossRefGoogle Scholar
  20. Prasad A K S K, Livingston R J, Ray G L. 1989. The marine epizoic diatom Falcula hyalina from Choctawhatchee Bay, the Northwestern Gulf of Mexico: frustule morphology and ecology. Diatom Research, 4(1): 119–129, doi: CrossRefGoogle Scholar
  21. Riaux-Gobin C, Witkowski A, Kociolek J P, et al. 2017a. New epizoic diatom (Bacillariophyta) species from sea turtles in the Eastern Caribbean and South Pacific. Diatom Research, 32(1): 109–125, doi: CrossRefGoogle Scholar
  22. Riaux-Gobin C, Witkowski A, Chevallier D, et al. 2017b. Two new Tursiocola species (Bacillariophyta) epizoic on green turtles (Chelonia mydas) in French Guiana and Eastern Caribbean. Fottea, 17(2): 150–163, doi: CrossRefGoogle Scholar
  23. Rivera P S, Gonzalez H E, Barrales H L. 1986. Cingulum and valve morphology of Pseudohimantidium Hustedt & Krasske (Bacillariophyceae). Phycologia, 25(1): 19–27, doi: CrossRefGoogle Scholar
  24. Round F E, Crawford R M, Mann D G. 1990. The Diatoms. Biology and Morphology of the Genera. Cambridge: Cambridge University Press, 345–447Google Scholar
  25. Sar E A, Sunesen I. 2014. The epizoic marine diatom Sceptronema orientale (Licmophoraceae, Licmophorales): epitypification and emendation of specific and generic descriptions. Phytotaxa, 177(5): 269–279, doi: CrossRefGoogle Scholar
  26. Simonsen R. 1970. Protoraphidaceae, eine neue Familie der Diatomeen. Nova Hedwigia Beihefte (in German), 31: 377–394Google Scholar
  27. Skovgaard A, Saiz E. 2006. Seasonal occurrence and role of protistan parasites in coastal marine zooplankton. Marine Ecology Progress Series, 327: 37–49, doi: CrossRefGoogle Scholar
  28. Sullivan M J. 1993. The labiate process of the diatom Protoraphis hustedtiana var. nana Takano. Nova Hedwigia Beihefte, 106: 161–167Google Scholar
  29. Takano H. 1983. New and rare diatoms from Japanese marine waters-XI. Three new species epizoic on copepods. Bulletin of Tokai Regional Fisheries Research Laboratory, 111: 23–35Google Scholar
  30. Takano H. 1985. A small form of the marine diatom Protoraphis hustediana, epizoic on a snail. Bulletin of Tokai Regional Fisheries Research Laboratory, 117: 31–35Google Scholar
  31. Takano H. 1988. A bloom of Neosynedra provincialis in a maricultural tank. Diatom (in Japanese), 4: 17–19Google Scholar
  32. Takayanagi K, Nishiuchi K, Yokouchi K, et al. 2006. A possible collaboration with China on marine ecosystem research in the East China Sea. Japan Agricultural Research Quarterly, 40(1): 59–64, doi: CrossRefGoogle Scholar
  33. Voigt M. 1959. Nouvelle note concernant le genre Pseudohimantidium. Vie Milieu (in French), 10: 199–203Google Scholar
  34. Williams D M, Round F E. 1986. Revision of the genus Synedra Ehrenb. Diatom Research, 1(2): 313–339, doi: CrossRefGoogle Scholar
  35. Witkowski A, Lange-Bertalot H, Metzeltin D. 2000. Diatom flora of marine coasts I. In: Lange-Bertalot H, ed. Iconographia Diatomologica. Ruggell: A. R. G. Gantner Verlag Kommanditgesellschaft, 74–75Google Scholar

Copyright information

© Chinese Society for Oceanography and Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  1. 1.School of Life SciencesXiamen UniversityXiamenChina
  2. 2.Key Laboratory of Ministry of Education for Coastal and Wetland EcosystemsXiamen UniversityXiamenChina
  3. 3.State Key Laboratory of Marine Environmental ScienceXiamen UniversityXiamenChina

Personalised recommendations