Common Planktonic Protozoa in the Upper Great Lakes An Illustrated Guide Hunter J. Carrick Dept. of Biology and Great Lakes Center for Environmental Research and Education State University of New York College at Buffalo 1300 Elmwood Avenue Buffalo, New York 14222 Gary L. Fahnenstiel U.S. Dept. of Commerce Great Lakes Environmental Research Laboratory Lake Michigan Field Station 1431 Beach Street Muskegon, Michigan 49441 ( ACKNOWLEDGEMENTS------------~ We would like to thank the crew of the RIV Shenehon (B. Burns, J. Grimes, and D. Morse). J. Cavaletto, M. McCormick, and T. Patton assisted us in the field. Discussions with M.L. Pace, D. Scavia, E. Sherr, E.F. Stoermer, W.D. Taylor, and R.G. Wetzel were helpful. An earlier version of the manuscript was reviewed by P. Lavrentyev. This research was supported by an IAGLR scholarship award and a merit grant from the University of Michigan, School of Natural Resources. Support from The University of Florida Foundation, Inc. to C. L. Schelske sup­ ported HJC during part of the study. Technical editing provided by J. Hutchinson and C. Darnell. Design and electronic production by C. Darnell. This publication was funded in part by the Michigan Sea Grant College Program with funds from grant number NA89AA-D-SG083, from the National Sea Grant College Program, National Oceanic and Atmospheric Administration, U.S. Department of Com­ merce, and funds from the State of Michigan. The Michigan Sea Grant College Program is a cooperative program of the University of Michigan and Michigan State University. ( ii PLATES Plate I Figure 1. Desmarella sp. (epifluorescent, ca. 1,500x) Figure 2. Chromulina sp.1 (epifluorescent, ca. 2,000x) Figure 3. Chromulina minima (epifluorescent, ca. 2,000x) Figure 4. Ochromonas nana (epifluorescent, ca. 4,000x) Figure 5. Ochromonas ovalis (epifluorescent, ca. 1,400x) Figure 6. Dinobryon divergens (brightfield, ca. 1600x) Plate II Figure 7. Cryptaulax sp.1 (brightfield, ca. 3600x) Figure 8. Cryptomonas erosa (brightfield, ca. 1000x) Figure 9. Cryptomonas erosa var reflexa (brightfield, ca. 1700x) Figure 10. Cryptomonas ovata (brightfield, ca. 2500x) Figure 11. Katablepharis ovalis (brightfield, ca. 1900x) Figure 12. Rhodomonas lens (brightfield, ca. 2000x) Figure 13. Rhodomonas minuta (brightfield, ca. 3000x) Plate III Figure 14. Ceratium hirudinella (brightfield, ca. 400x) Figure 15. Gymnodinium helveticum (brightfield, ca. 800x) Figure 16. Gymnodinium varians (epifluorescent, ca. 1600x) Figure 17. Peridinium inconspicuum (brightfield, ca. 1200x) Figure 18. Chrysochromulina parva (brightfield, ca. 2000x) Plate IV Figure 19. Codonella cratera (brightfield, ca. 400x) Figure 20. Strobilidium sp.1 (brightfield, ca. 800x) Figure 21. Strobilidium velox (brightfield, ca. lOOOx) Figure 22. Tintinnidium sp .1 (brightfield, ca. 1OOOx) Plate V Figure 23. Pelagohalteria sp.l (brightfield, ca. 800x) Figure 24. Strombidium sp.l (brightfield, ca. 1000x) Figure 25. Pelagostrombidium sp.1 (brightfield, ca. 1000x) Figure 26. Askenasia sp.2 (brightfield, ca. 400x) Figure 27. Lagynophyra sp.1 (brightfield, ca. 1000x) Figure 28. Mesodinium sp. (brightfield, ca. 400x) Figure 29. Monodinium sp.2 (brightfield, ca. 1000x) Plate VI Figure 30. Pseudobalanion sp. (brightfield, ca. 800x) Figure 31. Urotricha sp.l (brightfield, ca. 700x) Figure 32. Coleps sp.2 (brightfield, ca. 800x) Figure 33. Vaginacola sp. (brightfield, ca. 1000x) Figure 34. Vorticella sp.1 (brightfield, ca. 1000x) Figure 35. Vorticella campanula (brightfield, ca. 600x) iv CONTENTS ( SUMMARY .......................................................................................................................... 1 INTRODUCTION ................................................................................................................ 1 SCOPE OF WORK AND OBJECTIVES ............................................................................ 2 METHODOLOGY ............................................................................................................... 3 Sample Collection and Enumeration ........................................................................ 3 Ambient Water Column Conditions ......................................................................... 6 KEY TO THE COMMON PROTOZOAN ORDERS ( OCCURRING IN THE UPPER GREAT LAKES ......................................................... 7 KEY TO THE COMMON PROTOZOAN TAXA OCCURRING IN THE UPPER GREAT LAKES ......................................................... 8 TAXONOMIC PROFILES ................................................................................................... 11 Sarcomastigophora Choanoflagellida....................................................................................................... 11 Chrysomonadida ....................................................................................................... 13 Cryptomonadida ....................................................................................................... 19 Dinoflagellida ........................................................................................................... 27 Prymnesiida .............................................................................................................. 32 Ciliophora Choreotrichida .......................................................................................................... 34 Oligotrichida ............................................................................................................. 39 Haptorida .................................................................................................................. 43 Prorodontida ............................................................................................................. 48 Sessilida .................................................................................................................... 52 SUMMARY .......................................................................................................................... 56 REFERENCES ..................................................................................................................... 58 TABLE 1. The taxonomic position (Order, Taxon) of 35 common planktonic flagellated (Sarcomastigophora) and ciliated (Ciliophora) protists observed in the upper Great Lakes [where present (X), absent(-), and not sampled(?)] .......................................................................................... 4 iii SUMMARY This guide provides a body of taxonomic and ecological information about the planktonic protozoa that commonly occur in the upper Great Lakes (Lakes Huron, Michigan, and Superior). Our observations are based on more than 70 field collections obtained over a 10-year period (1979- 1989) from offshore locations in these lakes using techniques readily available to most ecologists (light and epifluorescence microscopy). A separate taxonomic profile for each of 35 common protozoan taxa encoun­ tered is presented. The analysis is organized around six general aspects of each organism's ecology that include: taxonomic position, morphological description, distribution, a brief list of pertinent references, general com­ ments (and observations), and a micrograph of the organism. Moreover, dichotomous keys to common protozoan orders and individual taxa are presented. We conclude that planktonic protozoa are an important compo­ nent of the plankton in these lakes and, thus, need to be accounted in future studies. While this guide is not intended as a definitive taxonomic work, it is a holistic compilation of data that should prove valuable to those inter­ ested in freshwater, planktonic protozoa. INTRODUCTION The quantitative importance of protozoa in aquatic systems has not been realized until recently (Sherr and Sherr, 1984). The abundance, biomass, and seasonal dynamics of protozoan populations in both marine (e.g., Sorokin, 1977; Davis and Sieburth, 1982; Sherr et al., 1984), and to a lesser extent, freshwater (Beaver and Crisman, 1982; Pace, 1982; Pick and Caron, 1987; Taylor and Heynen, 1987; Nagata, 1988) systems, suggests that protozoan biomass rivals that of traditionally larger (> 200 J..lm in size) zooplankton (Taylor and Heynen, 1987; Carrick and Fahnenstiel, 1990). High growth and production rates for protozoa (e.g., Sherr et al., 1984; Nagata, 1988) indicate that these organisms may consume a greater per­ centage of microbial production (bacteria and < 20-J..lm phytoplankton) compared with larger zooplankton (e.g., Verity, 1986). Protozoa also play an important role as remineralizers of nutrients by virtue of their high grazing rates on bacteria and small algae (Goldman et al., 1985; Anderson et al., 1986). In the Great Lakes, the quantitative importance of heterotrophic (Scavia et al., 1986; Scavia and Laird, 1987) and phototrophic (Caron et al., 1985; Fahnenstiel et al., 1986; Pick and Caron, 1987; Fahnenstiel and Carrick, 1992) picoplankton has been demonstrated. Higher bacterial production compared with primary production (annual averages) in Lake Michigan lends credence to the idea that ecosystem dynamics are largely governed by 1 a detrital food web (Scavia, 1988). Protozoan production in Lake Michigan is comparable with bacteria (Carrick et al., 1992) and can account for the constancy in bacterial abundances (Scavia and Laird, 1987). While some data exist on the distribution and composition of protozoa in the Great Lakes (Pick and Caron, 1987; Taylor and Heynen, 1987; Carrick and Fahnenstiel, 1989, 1990), no working