Bosmina coregoni
Bosmina coregoni
(water flea)
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Bosmina coregoni Baird, 1857

Common name: water flea

Synonyms and Other Names: Eubosmina coregoni

Taxonomy: available through www.itis.govITIS logo

Identification: Females of this water flea exhibit larger and more variable traits with respect to the carapace and antennules than do males. The females’ large antennules are located anteriorly and ventrally. The females’ postabdominal claw is emarginate near the tip and has proximal pecten only, with 3–5 short spines. That of the male becomes very narrow distally. The anterior sensory bristle of this species is near the end of the rostrum and close to the attachment of the antennules. There is no mucro or the mucro is extremely small. The lateral headpore is close to the attachment of the mandibles but relatively far from the headshield (Deevey and Deevey 1971; Pennak 1989; Dodson and Frey 1991; Lord et al. 2006).

Size: from 0.2 to 0.8 mm in length (Pennak 1989; Barbiero and Tuchman 2004)

Native Range: Eubosmina coregoni is native to Europe (Haney and Taylor 2003).

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Nonindigenous Occurrences: First known occurrence in the US was in 1966 from Lake Michigan; by the 1970s–1980s it was considered to have spread to all the Great Lakes and by the 1990s it was present in many inland lakes within 100 km of the Great Lakes (Mills et al. 1993; Demelo and Hebert 1994).  It should be noted that in a relatively recent survey, this species was not found in Lake Superior (Barbiero et al. 2001).

Found in New York in the Delta Reservoir, Blanheim Gilboa Reservoir, Cross Lake, Franklin Falls Pond, Ensign Pond and Snyders Lake; found in 1968 in the Pymatuning Reservoir in Pennsylvania; most recently reported from Lake Champlain, Vermont in 1994.            

Ecology: Found in freshwater ponds and lakes.  Algae-eating cladoceran; in less populated, homeostatic waters, E. coregoni infrequently reproduces sexually and instead maintains populations by parthenogenic females; maximum populations are found in late June in the US.

The distribution of E. coregoni varies seasonally in the Great Lakes. In Lake Michigan, it occurs in the nearshore region at 5–10 m from the surface in fall and winter, but more frequently at 20–30 m depth in the height of the summer. In the same lake, it is relatively uniformly distributed horizontally in fall and winter, but in summer it occurs significantly more frequently in water 0–18 km from shore than in open water. When it occurs predominantly at the surface in Lake Michigan, E. coregoni is an important food item for such fish species as bloater (Coregonus hoyi) (Gannon 1975, 1976; Evans et al. 1980; Crowder and Crawford 1984).            

In eutrophic lakes in Europe, E. coregoni is often dominant in spring and fall. However, in the Great Lakes it is almost completely absent in spring and is more abundant in summer, potentially reaching densities of around 69,000 per m2 in western Lake Erie and around 44,500 per m2 in Lake Ontario. It has also been recorded at high densities in the fall in Lake Ontario and Lake Michigan (Roth and Stewart 1973; Geller and Müller 1981; Johansson and O’Gorman 1991; Barbiero et al. 2001).        

Eubosmina coregoni filter feeds and feeds raptorially, selecting specific phytoplankton in the water column. It specifically selects particles of 0.5–5 μm in size and thus is much more tolerant of eutrophic conditions and the presence of cyanobacteria such as Cylindrospermopsis raciborskii than many larger Daphnia spp. Larger cladocerans experience difficulty feeding in the presence of cyanobacteria because they do not feed selectively and longer algae filaments clog their filtering apparatuses (Henning et al. 1991; Mayer et al. 1997; Cyr 1998; Donabaum et al. 1999).            

Reproduction in E. coregoni can occur either between sexual females and males, or parthenogenetically in asexual females. The mean number of eggs found per individual from 1981–1986 in Lake Ontario ranged from around 0.4–1.2. E. coregoni can produce resting eggs that can stay dormant in the sediments for long periods of time. These eggs will hatch under the influence of specific environmental conditions. For example, E. coregoni was once recorded to emerge from resting eggs after a drought and the re-acidification of a lake in Sudbury, Canada (Johansson and O’Gorman 1991; Arnott and Yan 2002; Lord et al. 2006).            

Changes in this species’ morphology with season, or cyclomorphosis, may be related to predation and/or temperature. Further studies need to be carried out to test these hypotheses, especially in North America. Most studies have been carried out in Europe, but different forms of this species occur in Europe in comparison with North America (Kappes and Sinsch 2002).            

This is a freshwater species. It can experience mortality at salinities of 3‰ (Nauwerck 1991).

Means of Introduction: Eubosmina coregoni was very likely introduced via ballast water to the Great Lakes and transferred within the network of ports by further ballast water movement and exchange. It probably expanded into inland lakes via long-distance dispersal and migration (Mills et al. 1993; Demelo and Hebert 1994).

Suchy and Hann (2007) suggested that the transfer of E. coregoni in the digestive tract of rainbow smelt (Osmerus mordax) may be responsible for introducing the species to water bodies west of the Laurentian Great Lakes, demonstrating how waterflea resting eggs may transform biological predation from a form of control to a vector for transport.

Status: Established throughout all the Great Lakes drainages; however, status in Lake Superior is uncertain.

One of the dominant zooplankton species in the Great Lakes; average numbers from a 1970 sample of Otsego Lake showed densities of 30,000 organisms per m3.

Impact of Introduction:

A) Realized: It is possible that the presence of E. coregoni and that of zebra mussel veligers (Dreissena polymorpha) in the zooplankton in Lake Ontario could have aided the establishment of the exotic blueback herring (Alosa aestivalis). E. coregoni also serves as a food item to introduced alewife (A. pseudoharengus) and the introduced spiny waterflea (Bythotrephes longimanus) in the Great Lakes (Mills et al. 1995; Molloy et al. 1997; Grigorovich et al. 1998).  

B) Potential: Unknown.

Remarks: After the introduction of B. longimanus to the Great Lakes, populations of E. coregoni greatly decreased in the mid to late 1980s and have remained at lower densities since this time. Population decreases in E. coregoni that occurred in the 1980s in Severn Sound, Lake Huron could also have been related to changes in fish community structure (Gemza 1995; Barbiero and Tuchman 2004).

References: (click for full references)

Arnott, S.E., and N.D. Yan. 2002. The influence of drought and re-acidification on zooplankton emergence from resting stages. Ecological Applications 12(1): 138-153.

Barbiero, R.P., and M.L. Tuchman. 2004. Changes in the crustacean communities of Lakes Michigan, Huron, and Erie following the invasion of the predatory cladoceran Bythotrephes longimanus. Canadian Journal of Fisheries and Aquatic Sciences 61: 2111-2125.

Barbiero, R.P., R.E. Little, and M.L. Tuchman. 2001. Results from the U.S. EPA’s biological open water surveillance program of the Laurentian Great Lakes: III. Crustacean zooplankton. Journal of Great Lakes Research 27(2): 167-184.

Crowder, L.B., and H.L. Crawford. 1984. Ecological shifts in resource use by bloaters in Lake Michigan. Transactions of the American Fisheries Society 113: 694-700.

Cyr, H. 1998. Cladoceran- and copepod-dominated zooplankton communities graze at similar rates in low-productivity lakes. Canadian Journal of Fisheries and Aquatic Sciences 55: 414-422.

Deevey, E.S., Jr., and G.B. Deevey. 1971. The American species of Eubosmina seligo (Crustacea, Cladocera). Limnology and Oceanography 16(2): 201-218.

Demelo, R., and P.D.N. Hebert. 1994. Founder effects and geographical variation in the invading cladoceran Bosmina (Eubosmina) coregoni Baird 1857 in North America. Heredity 73(5): 490-499.

Dodson, S.I., and D.G. Frey. 1991. Copepoda. Pp. 723-786 in J. H. Thorp and A. P. Covich, eds. Ecology and Classification of North American Freshwater Invertebrates. Academic Press, Inc., San Diego, California. 911 pp.

Donabaum, K., M. Schagerl, and M.T. Dokulil. 1999. Integrated management to restore macrophyte domination. Hydrobiologia 395/396: 87-97.

Evans, M.S., B.E. Hawkins, and D.W. Sell. 1980. Seasonal features of zooplankton assemblages in the nearshore area of southeastern Lake Michigan, USA. Journal of Great Lakes Research 6(4): 275-289.

Gannon, J.E. 1975. Horizontal distribution of crustacean zooplankton along a cross-lake transect in Lake Michigan. Journal of Great Lakes Research 1(1): 79-91.

Gannon, J.E. 1976. The effects of differential digestion rates of zooplankton by alewife, Alosa pseudoharengus, on determinations of selective feeding. Transactions of the American Fisheries Society 105(1): 89-95.

Geller, W., and H. Müller. 1981. The filtration apparatus of Cladocera: filter mesh-sizes and their implications on food selectivitiy. Oecologia 49: 316-321.

Gemza, A.F. 1995. Zooplankton seasonal dynamics and community structure in Severn Sound, Lake Huron. Water Quality Research Journal of Canada 30(4):673-691.

GLMRIS. 2012. Appendix C: Inventory of Available Controls for Aquatic Nuisance Species of Concern, Chicago Area Waterway System. U.S. Army Corps of Engineers.

Grigorovich, I.A., O.V. Pashkova, Y.F. Gromova, and C.D. van Overdijk. 1998. Bythotrephes longimanus in the Commonwealth of Independent States: variability, distribution and ecology. Hydrobiologia 379: 183-198.

Haney, R.A., and D.J. Taylor. 2003. Testing paleolimnological predictions with molecular data: the origins of Holarctic Eubosmina. Journal of Evolutionary Biology 16(5): 871-882.

Havens, K.E. 1994. An experimental comparison of the effects of two chemical stressors on a freshwater zooplankton assemblage. Environmental Pollution 84(3):245-251.

Henning, M., H. Hertel, H. Wall, and J.-G. Kohl. 1991. Strain-specific influence of Microcystis aeruginosa on food ingestion and assimilation of some cladocerans and copepods. Internationale Revue der Gesamten Hydrobiologie 76(1): 37-45.

Johansson, O.E., and R.O’Gorman. 1991. Roles of predation, food, and temperature in structuring the epilimnetic zooplankton populations in Lake Ontario, 1981-1986. Transactions of the American Fisheries Society 120: 193-208.

Kappes, H., and U. Sinsch. 2002. Temperature- and predator- induced phenotypic plasticity in Bosmina cornuta and B. pellucida (Crustacea: Cladocera). Freshwater Biology 47(10): 1944-1955.

Lord, H., R. Lagergren, J.-E. Svensson, and N. Lundgvist. 2006. Sexual dimorphism in Bosmina: the role of morphology, drag, and swimming. Ecology 87(3): 788-795.

Marshall, J.S., D.L. Mellinger, and J.I. Parker. 1981. Combined effects of cadmium and zinc on a Lake Michigan zooplankton community. Journal of Great Lakes Research 7(3):215-223.

Mayer, J., M.T. Dokulil, M. Salbrechter, M. Berger, T. Posch, G. Pfister, A.K.T. Kirschner, B. Velimirov, A. Steitz, and T. Ulbricht. 1997. Seasonal successions and trophic relations between phytoplankton, zooplankton, ciliate and bacteria in a hypertrophic shallow lake in Vienna, Austria. Hydrobiologia 342/343: 165-174.

Mills, E.L., J.H. Leach, J.T. Carlton, and C.L. Secor. 1993. Exotic species in the Great Lakes: a history of biotic crises and anthropogenic introductions. Journal of Great Lakes Research 19(1): 1-54.

Mills, E.L., R. O’Gorman, E.F. Roseman, C. Adams, and R.W. Owens. 1995. Planktivory by alewife (Alosa pseudoharengus) and rainbow smelt (Osmerus mordax) on microcrustacean zooplankton and dreissenid (Bivalvia: Dreissenidae) veligers in southern Lake Ontario. Canadian Journal of Fisheries and Aquatic Sciences 52: 925-935.

Molloy, D.P., A.Y. Karatayev, L.E. Burlakova, D.P. Kurandina, and F. Laruelle. 1997. Natural enemies of zebra mussels: predators, parasites, and ecological competitors. Reviews in Fisheries Science 5: 27-97.

Nauwerck, A. 1991. The history of the genus Eubosmina in Lake Mondsee (upper Austria). Hydrobiologia 225: 87-103.

Ontario's Invading Species Awareness Program. Spiny and Fishhook Waterfleas. Accessed on 05/31/2013.

Pennak, R. 1989. Fresh-water Invertebrates of the Unites States, 3rd ed. Protozoa to Mollusca. John Wiley & Sons, Inc., New York, New York State. 628 pp.

Ricciardi, A. 2001. Facilitative interaction among aquatic invaders: is an “invasional meltdown” occurring in the Great Lakes? Canadian Journal of Fisheries and Aquatic Sciences 58(12): 2513-2525.

Roth, J.C., and J.A. Stewart. 1973. Nearshore zooplankton of southeastern Lake Michigan, 1972. Pp. 132-142 in International Association of Great Lakes Research, Proceedings 16th Conference Great Lakes Research.

Suchy, K.D. and B.J. Hann. 2007. Using microfossil remains in lake sediments to examine the invasion of Eubosmina coregoni (Cladocera, Bosminidae) in Lake of the Woods, Ontario, Canada. Journal of Great Lakes Research 33(4):867-874.

Other Resources:
Great Lakes Water Life

Author: Kipp, R.M., A.J. Benson, J. Larson, T.H. Makled, and A. Fusaro

Revision Date: 6/10/2013

Citation Information:
Kipp, R.M., A.J. Benson, J. Larson, T.H. Makled, and A. Fusaro, 2017, Bosmina coregoni Baird, 1857: U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL,, Revision Date: 6/10/2013, Access Date: 9/21/2017

This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.

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Citation information: U.S. Geological Survey. [2017]. Nonindigenous Aquatic Species Database. Gainesville, Florida. Accessed [9/21/2017].

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