Microbial biogeography through the lens of exotic species: the recent introduction and spread of the freshwater diatom Discostella asterocostata in the United States

Andrew J. Alverson, Tyler K. Chafin, Kiley A. Jones, Kalina M. Manoylov, Hillary Johnson, Matthew L. Julius, Teofil Nakov, Elizabeth C. Ruck, Edward C. Theriot, Kevin M. Yeager, Jeffery R. Stone

Research output: Contribution to journalArticlepeer-review

1 Scopus citations


The large population sizes and high dispersal potential of microbes suggests that a given microbial species should be found in all suitable habitats worldwide. Consequently, microbes should not exhibit the kinds of biogeographic patterns seen in macroorganisms. This paradigm is challenged by a growing list of exotic microbes with biogeographic disjunctions that instead promotes microbial dispersal as inherently limited. We sampled water bodies in the United States and compiled records from the literature and public databases to characterize the distribution of the freshwater planktonic diatom, Discostella asterocostata (Xie, Lin, and Cai) Houk and Klee. Discostella asterocostata was thought to be restricted to the Far East, but we report its presence in ecologically similar water bodies across the eastern United States. Populations from the U.S. and China are indistinguishable morphometrically, suggesting they may be recently separated—a hypothesis supported by paleolimnological data, which support an introduction of D. asterocostata into the U.S. as recently as the mid-1980s. The overlapping distributions of D. asterocostata and invasive carp species, in both their native and nonnative ranges, highlighted Asian carp as a possible vector for introduction of the diatom in the U.S. The existence of exotic diatoms underscores natural constraints on microbial dispersal, resulting in biogeographic distributions that can be upended through human activity.

Original languageEnglish
Pages (from-to)2191-2204
Number of pages14
JournalBiological Invasions
Issue number7
StatePublished - Jul 2021

Bibliographical note

Funding Information:
Research was supported by the ISU Center for Student Research and Creativity, the ISU Department of Earth and Environmental Systems, the ISU Summer Undergraduate Research Experience program. This work was also supported by the National Science Foundation (Grant Number DEB-1651087 to AJA), a Student Undergraduate Research Fellowship from the Arkansas Department of Higher Education to KAJ, and multiple awards from the Arkansas Biosciences Institute to AJA.

Funding Information:
We thank Anna Yu for help obtaining the isotype material and Don Charles for facilitating access to public databases. Sediment cores were collected, subsampled, and processed for this project by Erika Smith, Helena Bierly, Ken Cleghorn, Jared Foster, and Corey Portwood.

Publisher Copyright:
© 2021, The Author(s), under exclusive licence to Springer Nature Switzerland AG.


  • Asian carp
  • Baas–Becking hypothesis
  • Bighead carp
  • Freshwater
  • Reservoirs
  • Silver carp

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Ecology


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