Summary 3

Woronichinia is a cyanobacteria genus that is found in freshwater phytoplankton assemblages. In nutrient-rich lakes it can form dense blooms. Woronichinia naegeliana is the most common species associated with toxic cyanobacteria bloom. Woronichinia naegeliana blooms usually contain other toxic cyanobacteria, so it can be difficult to determine whether Woronichinia is contributing toxins.

Description 3

Individual Woronichinia naegeliana cells are oval or broadly elliptical and tiny (3-5 μm, or about the width of a strand of spider silk). Each cell is located at the end of a wide mucilage tube that is difficult to see without staining. The cells are arranged in a dense peripheral layer around a hollow center, forming spherical, oval, or irregular colonies. Under magnification the cells are greenish brown or dark brown, and appear granular or mottled due to the presence of gas vesicles in the cells. Woronichinia naegeliana colonies may extrude cells as the colony ages or is stressed (e.g., when compressed by a coverslip).

Woronichinia naegeliana closely resembles Coelosphaerium, which is another type of cyanobacteria that forms spherical colonies (see Synonyms). Coelosphaerium cells are usually pale or bright bluegreen, most species do not have gas vesicles, and the cells are not located at the ends of mucilage tubes (hard to see).

Ecology 3

Woronichinia naegeliana blooms often form during warm, calm weather in lakes and ponds with relatively high nutrient concentrations (nitrogen or phosphorus) or low nitrogen to phosphorus ratios (N:P<15).

  • Recent work suggests that high total phosphorus (TP) or total nitrogen (TN) concentrations are better predictors of bloom formation than N:P ratios.
  • Woronichinia does not fix atmospheric nitrogen, but is very efficient in taking up ammonium and urea, and often forms blooms when nitrogen concentrations are limiting to other algae.
  • The gas vesicles in Woronichinia cells provide a mechanism to move up and down in the water column, which increases access to nutrients and other growth factors.

Woronichinia blooms usually contain other types of Cyanobacteria, especially Aphanizomenon , Dolichospermum (aka Anabaena), Gloeotrichia, and Microcystis.

Woronichinia colonies often have the epiphyte Stylosphaeridium (green algae) attached to the colony surface.

Toxicity 3

Identifying which cyanobacteria species are producing toxins is more difficult that it sounds. Historically, cyanobacteria taxa were described as "potentially" toxic based on whether they were collected in a toxic bloom. With the advancement of culturing techniques and genetic analysis, toxicity information is becoming more exact. But this is an ongoing process, so the toxicity information on these pages should be considered a work in progress.

Until recently, there was little known about whether Woronichinia cells were capable of producing toxins. Recent studies, however, revealed that Woronichinia naegeliana can produce anatoxins (nerve toxin), microcystins (liver toxin), microginins (liver toxin), and other less common toxins.

  • Anatoxins are rapidly degraded by sunlight and at pH levels that are slightly above neutral (neutral pH = 7.0). At low pH levels, and in the absence of light, anatoxins may persist in the aquatic environment for a few weeks.
  • Microcystins are rapidly degraded by naturally occurring but specialized bacteria.
  • If the specialized bacteria are not present, microcystins can persist in the aquatic environment for months.
  • Not much is known about decomposition rates for microginins, except that they appear to be relatively stable in the aquatic environment.

In addition to any toxins produced by Woronichinia, blooms containing Woronichinia naegeliana typically contain other potentially toxic cyanobacteria, including Dolichospermum and Microcystis.

Similar Genera 3

  • Cyanobacteria: Aphanocapsa, Aphanothece, Coelosphaerium, Gomphosphaeria, Microcystis, Pannus, Snowella
  • Green Algae: Sphaerocystis, Volvox
  • Other: Sphaeroeca, Sulfur bacteria

Information Sources 3

  • Bennett, L. 2017. Algae, cyanobacteria blooms, and climate change. Climate Institute Report, April 2017.
  • Berg, M and M. Sutula. 2015. Factors affecting the growth of cyanobacteria with special emphasis on the Sacramento-Jan Joaquin Delta. Southern California Coastal Water Research Project Technical Report 869.
  • Bober, B. and J. Bialczyk. 2017. Determination of the toxicity of the freshwater cyanobacteria Woronichinia naegeliana (Unger) Elenkin. J. Appl. Phycol. 29:1355-1362.
  • Caldwell Eldridge, S., R. Wood, and K. Echols. 2012. Spatial and temporal dynamics of cyanotoxins and their relation to other water quality variables in Upper Klamath Lake, Oregon, 2007-09. USGS Scientific Investigations Report 2012-5069.
  • Chorus, I. and J. Bartram (Eds). 1999. Toxic cyanobacteria in water: a guide to their public health consequences, monitoring and management. The World Health Organization E & FN Spon, London.
  • D'Anglada, L., J. Donohue, J. Strong, and B. Hawkins. 2015. Health effects support document for the cyanobacterial toxin anatoxin-A. U.S. Environmental Protection Agency, Office of Water, EAP-820R15104, June 2015.
  • EPA. 2014. Cyanobacteria and Cyanotoxins: Information for Drinking Water Systems. U. S. Environmental Protection Agency, Office of Water, EPA-810F11001.
  • Graham, L. E., J. M. Graham, L. W. Wilcox, and M. E. Cook. 2016. Algae, Third Ed., ver 3.3.1 . LJLM Press, ww.ljlmpress.com.
  • Gury, M. D. and G. M. Guiry. 2017. AlgaeBase. world-wide electronic publication, National University of Ireland, Galway. http://www.algaebase.org; searched on 15 March 2018.
  • Matthews, Robin A., "Freshwater Algae in Northwest Washington, Volume I, Cyanobacteria" (2016). A Collection of Open Access Books and Monographs. 6. http://cedar.wwu.edu/cedarbooks/6 (also see: http://www.wwu.edu/iws/).
  • Meriluoto, J., L. Spoof, and G. Codd. 2017. Handbook of Cyanobacterial Monitoring and Cyanotoxin Analysis. John Wiley & Sons, Chichester, UK.
  • Paerl, H. W. 2014. Mitigating harmful cyanobacterial blooms in a human- and climatically-impacted world. Life 2014 4:988-1012.
  • Walsby, A. E. 1994. Gas vesicles. Microbiological Reviews 58:94-144

Synonyms 4

Woronichinia naegeliana is synonymous with Coelosphaerium naegelianum and Gomphosphaeria naegeliana

About 5

This guide was prepared by Dr. Robin Matthews, former Director of the Institute for Watershed Studies (http://www.wwu.edu/iws/) and professor emeritus at Western Washington University. In addition to this guide she has also written two ebooks (more on the way) on phytoplankton identification (see the "algae books" link on http://www.wwu.edu/iws/) and an online key to the cyanobacteria (http://www.snoringcat.net/cyanobacteria_key/index.html).

Sources and Credits

  1. (c) rmatth, some rights reserved (CC BY-NC-SA), uploaded by rmatth
  2. (c) Adam Heathcote, some rights reserved (CC BY-NC), uploaded by Adam Heathcote
  3. (c) rmatth, some rights reserved (CC BY-NC-SA)
  4. Adapted by Bryan Milstead from a work by (c) rmatth, some rights reserved (CC BY-NC-SA)
  5. Adapted by rmatth from a work by (c) Bryan Milstead, some rights reserved (CC BY-NC-SA)

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