The Nonindigenous Occurrences section of the NAS species profiles has a new structure. The section is now dynamically updated from the NAS database to ensure that it contains the most current and accurate information. Occurrences are summarized in Table 1, alphabetically by state, with years of earliest and most recent observations, and the tally and names of drainages where the species was observed. The table contains hyperlinks to collections tables of specimens based on the states, years, and drainages selected. References to specimens that were not obtained through sighting reports and personal communications are found through the hyperlink in the Table 1 caption or through the individual specimens linked in the collections tables.

Hemimysis anomala
Hemimysis anomala
(bloody red shrimp)
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Hemimysis anomala G.O. Sars, 1907

Common name: bloody red shrimp

Taxonomy: available through www.itis.govITIS logo

Identification: This freshwater shrimp can be ivory-yellow in color or translucent, but exhibits pigmented red chromatophores in the carapax and telson (Janas and Wysocki 2005; Salemaa and Hietalahti 1993). The intensity of coloration varies with contraction or expansion of the chromatophores in response to light and temperature conditions; in shaded areas, individuals tend to have a deeper red color (Ketelaars et al. 1999; Pothoven et al. 2007; Salemaa and Hietalahti 1993). Juveniles are more translucent than adults (Ketelaars et al. 1999). Preserved individuals may lose their color. Hemimysis anomala is distinguishable from other mysid species including the Great Lakes' native opossum shrimp, Mysis relicta (identified in some recent scientific literature as Mysis diluviana), by its truncated telson (tail) with a long spine at both corners; in contrast, M. diluviana has a forked telson (Holdich et al. 2006; Ketelaars et al. 1999; Salemaa and Hietalahti 1993).

Size: Mature individuals range from 6 to 13 mm in length (Borcherding et al. 2006; Janas and Wysocki 2005; Salemaa and Hietalahti 1993). Females are slightly larger than males.

Native Range: Hemimysis anomala is native to freshwater margins of the Black Sea, the Azov Sea and the eastern Ponto-Caspian Sea. It has historically occurred in the lower reaches of the Don, Danube, Dnieper and Dniester rivers.

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Hydrologic Unit Codes (HUCs) Explained
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Nonindigenous Occurrences: Hemimysis anomala was reported for the first time in 2006 from two disjunct regions in the Great Lakes: southeastern Lake Ontario at Nine Mile Point near Oswego, New York, in May 2006 (J. Wyda 2007, personal communication); and from a channel connecting Muskegon Lake to Lake Michigan in November 2006 (Pothoven et al. 2007). Specimens resembling H. anomala have also been found in the stomach contents of a white perch collected near Port Dover, Lake Erie in August 2006 (T. MacDougall, Ontario Ministry of Natural Resources, pers, comm.). The species is probably present at other locations in the Great Lakes basin, but has escaped detection.

Table 1. States with nonindigenous occurrences, the earliest and latest observations in each state, and the tally and names of HUCs with observations†. Names and dates are hyperlinked to their relevant specimen records. The list of references for all nonindigenous occurrences of Hemimysis anomala are found here.

StateYear of earliest observationYear of last observationTotal HUCs with observations†HUCs with observations†
Illinois200620163Lake Michigan; Little Calumet-Galien; Pike-Root
Indiana201620161Lake Michigan
Michigan200620166Boardman-Charlevoix; Lake Erie; Lake Huron; Lake Michigan; Muskegon; Pere Marquette-White
New York200620164Lake Erie; Lake Ontario; Oneida; Seneca
Ohio200920111Lake Erie
Wisconsin200720186Beartrap-Nemadji; Door-Kewaunee; Lake Michigan; Lake Superior; Lower Fox; Milwaukee

Table last updated 10/10/2018

† Populations may not be currently present.

Ecology: Most mysid species are found in marine environments, but 3% (25 species) inhabit fresh to brackish water. Hemimysis anomala is a brackish-water mysid able to adapt to freshwater environments (Pienimäki and Leppäkoski 2004; Jazdzewski et al. 2005). It tolerates salinity concentrations of 0–19 ppt (Bij de Vaate et al. 2002; Borcherding et al. 2006) and prefers water temperatures of 9–20°C. Populations may survive temperatures of 0°C over winter, but not without substantial mortality (Borcherding et al. 2006).

This species is normally found in lentic waters, although it has successfully established in European rivers (Bij de Vaate et al. 2002; Holdich et al. 2006). Individuals remain near profundal sediments during the day, migrate in swarms to the upper water column at twilight, then return to the profundal zone at dawn (Borcherding et al. 2006; Janas and Wysocki 2005). Only males tend to undergo these migrations. Juvenile H. anomala often inhabit different positions (usually higher) in the water column than adults, possibly to avoid cannibalism (Ketelaars et al. 1999). Being more transparent, juveniles may be less at risk of fish predation than adults. The adults are fast swimmers, moving at several centimeters per second when alarmed (Borcherding et al. 2006). The bloody-red mysid has been collected at depths ranging from 0.5 m to 50 m, although it generally inhabits 6 m to 10 m depths (Salemaa and Hietalahti 1993). It favors rocky substrate (Janas and Wysocki 2005), is less abundant on soft sediments, and is usually scarce in areas of dense vegetation or high siltation (Pothoven et al. 2007). It generally avoids areas where other mysid species are found (Salemaa and Hietalahti 1993).

Its tendency to aggregate creates locally dense swarms up to several square meters in area (Dumont 2006). Hemimysis anomala breeds from April to September/October. Sexual maturity occurs in <45 days. Females become ovigerous at 8–9°C and produce 2 to 4 broods per year. Brood size is correlated with female length and ranges from 6 to 70 embryos per individual (Ketelaars et al. 1999; Salemaa and Hietalahti 1993; Borcherding et al. 2006). Extremely high densities of H. anomala (up to >6 ind/L) have been recorded in some invaded European reservoirs (Ketelaars et al. 1999).

Hemimysis anomala is an opportunistic omnivore that feeds primarily on zooplankton, particularly cladocerans, but also consumes detritus (plant and animal remains), phytoplankton (particularly green algae and diatoms), and insect larvae, and is occasionally cannibalistic (Ketelaars et al. 1999; Borcherding et al. 2006; Dumont 2006). Younger individuals (‹ 4mm total length) feed mainly on phytoplankton. The proportion of zooplankton consumed in the mysid's diet increases with its body size (Borcherding et al. 2006). A bloody-red mysid feeds using its thoracic limbs, either by capturing prey with its endopods or by removing food particles from its body that are filtered from incoming currents by its exopods (Borcherding et al. 2006; Ketelaars et al. 1999).

Means of Introduction: Hemimysis anomala was very likely introduced to the Great Lakes via ballast water release from transoceanic ships.

Status: The presence of juveniles and reproductive females within a dense population suggests that H. anomala is well established near Muskegon Lake in southern Lake Michigan (Pothoven et al. 2007) and at Nine Mile Point in Lake Ontario (J. Wyda, pers. comm.). A population density of 0.5 ± 0.1 individuals/L recorded at the Lake Michigan site (Pothoven et al. 2007) is already within the range found in some European reservoirs invaded by H. anomala, and is higher than maximum densities recorded for several other mysids (Ketelaars et al. 1999).

Impact of Introduction:

A) Realized: There are no recorded impacts yet associated with the recent introduction of this species to the Great Lakes.

B) Potential: Ponto-Caspian mysids differ from the North American mysid Mysis relicta, by their adaptation to warmer temperatures (Bondarenko and Yablonskaya 1979). Therefore, H. anomala could become abundant in many areas of the Great Lakes that are currently devoid of mysids. Judging by its impacts in some European reservoirs (Ketelaars et al. 1999), H. anomala may reduce zooplankton biomass and diversity in these areas, with cladocerans (particularly Daphnia), rotifers and ostracods being most affected (Ketelaars et al. 1999; Sinclair et al. 2016). H. anomala may compete with, or prey upon, other invertebrate predators, such as Bythotrephes longimanus and Leptodora kindti. Its omnivory may also reduce local phytoplankton if small-sized juvenile mysids are abundant (Ketelaars et al. 1999); however, phytoplankton biomass typically increases (sometimes doubling) in lakes following mysid invasions (Borcherding et al. 2006). Hemimysis feeds rapidly, even at low prey densities, and its fecal pellets may alter the local physico-chemical environment (Ketelaars et al. 1999; Olenin and Leppäkoski 1999; Pienimäki and Leppäkoski 2004). Hemimysis anomala is considered a high-energy food source due to its lipid content, which can increase growth rates for planktivores (Borcherding et al. 2006). In some lakes mysid (Mysis spp.) introductions have preceded the increased growth of salmonids, whereas in other lakes they are associated with rapid declines in abundance and productivity of pelagic fishes (Lasenby et al. 1986; Langeland et al. 1991; Spencer et al. 1991). A mysid introduction can also increase the biomagnification of contaminants in piscivores, through a lengthening of the food chain; for example, concentrations of polychlorinated biphenyls and mercury in fishes have been shown to be higher in lakes containing mysids than in mysid-free lakes (cf. Rasmussen et al. 1990; Cabana et al. 1994). Furthermore, through direct transmission and indirect effects on the food web, introduced mysids may cause increased parasitism by nematodes, cestodes and acanthocephalans in fishes (Lasenby et al. 1986; Northcote 1991).

Remarks: In southern Lake Michigan basin, females average 7 mm in length (Pothoven et al. 2007).

This Ponto-Caspian species was predicted to invade the Great Lakes because of its likelihood of surviving transport in ship ballast water and because it has an extensive recent invasion history in Europe, including establishment in the Baltic Sea basin. (Ricciardi and Rasmussen 1998). It was intentionally stocked in reservoirs of the Dnieper and Volga Rivers during the 1950s and '60s (Mordukhai-Boltovskoi 1979; Bubinas 1980; Pligin and Yemel'yanova 1989; Komarova 1991). It was discovered in the Baltic Sea in the Gulf of Finland in 1992 and subsequently spread 200 km along the coast (Salemaa and Hietalahti 1993; Lundberg and Svensson 2004). It was recorded in the Rhine River in 1997 (Borcherding et al. 2006), the Netherlands by 1998, Belgium by 1999, and the United Kingdom by 2004 (Holdich et al. 2006). Some of these introductions likely occurred via ballast water release, whereas most dispersal occurred through canals (Bij de Vaate et al. 2002; Salemaa and Hietalahti 1993). Hemimysis anomala is considered to be more invasive than several other Ponto-Caspian mysids currently expanding their ranges in Europe (Wittman 2006).

The port at Muskegon is not a high-traffic area for shipping; therefore, the population in Lake Michigan probably reflects an introduction from another invaded site in the Great Lakes. Hemimysis anomala's relatively low fecundity (Ketelaars et al. 1999) suggests that it may have been present in the Great Lakes a few years before being discovered. Monitoring of this species is made difficult by its nocturnal behavior and because of its rapid swimming and response to stimuli. Specialized benthic traps are useful for sampling cryptic populations (Borcherding et al. 2006). It may be detected at night by shining a bright light on calm water, which will cause individuals to rapidly disperse. During daylight hours, swarms may hide in the shade provided by rock crevices, boulders, piers and jetties.

Voucher Specimens: Canadian Museum of Nature, Ottawa CMNC 2007-0001

References: (click for full references)

Bij de Vaate, A., K. Jazdzewski, H.A.M. Ketelaars, S. Gollasch, and G. Van der Velde. 2002. Geographical patterns in range extension of Ponto-Caspian macroinvertebrate species in Europe. Canadian Journal of Fisheries and Aquatic Sciences 59: 1159-1174.

Bondarenko, M.V., and E.A. Yablonskaya. 1979. The rate of oxygen consumption by the mysid Paramysis lacustris (Czern.) from the northern Caspian Sea. In Effect of water management on the biological productivity of the Azov and Caspian seas. VNIRO, Moscow. pp. 65.69. (In Russian with English summary.)

Borcherding, J., S. Murawski, and H. Arndt. 2006. Population ecology, vertical migration and feeding of the Ponto-Caspian invader Hemimysis anomala in a gravel-pit lake connected to the River Rhine. Freshwater Biology 51: 2376-2387.

Brooking, T.E., L.G. Rudstam, S.D. Krueger, J.R. Jackson, A.B. Welsh, and W.W. Fetzer. 2010. First occurrence of the mysid Hemimysis anomala in an inland lake in North America, Oneida Lake. Journal of Great Lakes Research 36(3): 577-581.

Bubinas, A.D. 1980. Formation of benthic fauna as a food base for fish in the reservoir of the Kaunas hydro electric power plant, Lithuanian-SSR USSR. Lietuvos TSR Mokslu Akademijos Darbai Serija C Biologijos Mokslai 4: 91-96.

Cabana, G., A. Tremblay, J. Kalff, and J.B. Rasmussen. 1994. Pelagic food chain structure in Ontario lakes: a determinant of mercury levels in lake trout (Salvelinus namaycush). Canadian Journal of Fisheries and Aquatic Sciences 51: 381-389.

Dumont, S. 2006. Notes and News. A new invasive species in the north-east of France, Hemimysis anomala G. O. Sars, 1907 (Mysidacea). Crustaceana 79: 1269-1274.

Dumont, S., and C.D. Muller. 2009. Distribution, ecology and impact of a small invasive shellfish, Hemimysis anomala in Alsatian water. Biological Invasion 12(3): 495-500.

Ellis, S. and H.J. MacIsaac. 2009. Salinity tolerance of Great Lakes invaders. Freshwater Biology 54(1):77-89.

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

Holdich, D., S. Gallagher, L. Rippon, P. Harding, and R. Stubbington. 2006. The invasive Ponto-Caspian mysid, Hemimysis anomala, reaches the UK. Aquatic Invasions 1(1): 4-6.

Janas, U., and P. Wysocki. 2005. Hemimysis anomala G.O. Sars, 1907 (Crustacea, Mysidacea) – first record in the Gulf of Gdansk. Oceanologia 47: 405-408.

Jazdzewski, K., A. Konopacka, and M. Grabowski. 2005. Native and alien malacostracan crustacean along the Polish Baltic Sea coast in the twentieth century. Oceanological and Hydrobiological Studies XXXIV(suppl. 1): 175-193.

Ketelaars, H.A.M., F.E. Lambreqts-van de Clundert, C.J. Carpentier, A.J. Waqenvoort, and W. Hooqenboezem. 1999. Ecological effects of the mass occurrence of the Ponto-Caspian invader, Hemimysis anomala G.O. Sars, 1907 (Crustacea: Mysidacea), in a freshwater storage reservoir in the Netherlands, with notes on its autecology and new records. Hydrobiologia 394: 233-248.

Kestrup, Å.M., J.T.A. Dick, and A. Ricciardi. 2011. Interactions between invasive and native crustaceans: differential functional responses of intraguild predators towards juvenile hetero-specifics. Biological Invasions 13(3):731-737.

Komarova, T.I. 1989. Ecological and faunistic review of Mysidacea (Crustacea: Mysidae) in the Sea of Azov, USSR. Vestnik Zoologii 4: 3-7.

Langeland, A., J.I. Koksvik, and J. Nydal. 1991. Impact of the introduction of Mysis relicta on the zooplankton and fish populations in a Norwegian lake. American Fisheries Society Symposium 9: 98-114.

Lantry, B.F., M.G. Walsh, J.H. Johnson, and J.E. McKenna. 2010. Occurrence of the Great Lake’s most recent invader, Hemimysis anomala, in the diet of fishes in southeastern Lake Ontario. Journal of Great Lakes Research 36(1): 179-183.

Lasenby, D.C., T.G. Northcote, and M. Fürst. 1986. Theory, practice, and effects of Mysis introductions to North American and Scandinavian lakes. Canadian Journal of Fisheries and Aquatic Sciences 43: 1277-1284.

Lundberg, S., and J.E. Svensson. 2004. The mysid shrimp Hemimysis anomala G. O. Sars documented in Sweden. Fauna och Flora (Stockholm) 99(1): 38-40.

MacDougall, T. - Ontario Minsitry of Natural Resources.

Marty, J., K. Bowen, M.A. Koops, and M. Power. 2010. Distribution and ecology of Hemimysis anomala, the latest invader of the Great Lakes basin. Hydrobiologia 647(1):71-80.

Mordukhai-Boltovskoi, F.D. 1979. Composition and distribution of Caspian fauna in light of modern data. Internationale Revue der gesamten Hydrobiologie 64: 1-38.

Northcote, T.G. 1991. Success, problems, and control of introduced mysid populations in lakes and reservoirs. American Fisheries Society Symposium 9: 5-16.

Olenin, S., and E. Leppäkoski. 1999. Non-native animals in the Baltic Sea: alteration of benthic habitats in coastal inlets and lagoons. Hydrobiologia 393: 233-243.

Ontario's Invading Species Awareness Program. Bloody Red Shrimp Hemimysis anomala. http://www.invadingspecies.com/invaders/invertebrates/bloody-red-shrimp/. Accessed on 06/27/2013.

Pienimäki, M.E., and E. Leppäkoski. 2004. Invasion pressure on the Finnish Lake District: invasion corridors and barriers. 2004. Biological Invasions 6: 331-346.

Pligin, Y.V., and L.V. Yemel'yanova. 1989. Acclimatization of Caspian invertebrates in Dnieper reservoirs. Hydrobiological Journal 25: 1-9.

Pothoven, S.A., I.A. Grigorovich, G.L. Fahnenstiel, and M.D. Balcer. 2007. Introduction of the Ponto-Caspian bloody-red mysid Hemimysis anomala into the Lake Michigan basin. Journal of Great Lakes Research. 33: 285-292.

Rasmussen, J.B., Rowan, D.J., Lean, D.R.S., and Carey, J.H. 1990. Food chain structure in Ontario lakes determines PCB levels in lake trout (Salvelinus namaycush) and other pelagic fish. Canadian Journal of Fisheries and Aquatic Sciences 47: 2030-2038.

Ricciardi, A., and J. B. Rasmussen. 1998. Predicting the identity and impact of future biological invaders: a priority for aquatic resource management. Canadian Journal of Fisheries and Aquatic Sciences 55: 1759-1765.

Ricciardi, A., S. Avlijas, and J. Marty. 2011. Forcasting the ecological impacts of the Hemimysis anomala invasion in North America: Lessons from other freshwater mysid introductions. Journal of Great Lakes Research 38(2): 7-13.

Salemaa, H., and V. Hietalahti. 1993. Hemimysis anomala G. O. Sars (Crustacea: Mysidacea) – immigration of a Pontocaspian mysid into the Baltic Sea. Annales Zoologici Fennici 30(4): 271-276.

Sinclair, J. S., Arnott, S. E., and A. Cox. The quick and the dead: copepods dominate as cladocerans decline following invasion by Hemimysis anomala. Canadian Journal of Fisheries and Aquatic Sciences 73:793-803.

Spencer, C.N., B.R. McClelland, and J.A. Stanford. 1991. Shrimp stocking, salmon collapse, and eagle displacement. BioScience 44: 14-21.

Walsh, M.G., B.F. Lantry, B. Boscarino, K. Bowen, J. Gerlofsma, T. Schaner, R. Back, J. Questel, G.A. Smythe, R. Cap, M. Goehle, B. Young, M. Chalupnicki, J.H. Johnson, and J.E. McKenna. 2010. The early observations on an emerging Great Lakes invader Hemimysis anomala in Lake Ontario. Journal of Great Lakes Research 36(3) 499-504.

Wittman, K.J. 2006. Distribution and invasion potential of the Ponto-Capsian Mysidae (Mysidacea: Crustacea Malacostraca: Peracarida: Mysida). In Neobiota: From Ecology to Conservation (W.F. Rabitsch, F. Klingenstein and F. Essl, editors). Federal Agency for Nature Conservation, Vienna.

Wyda, J. - The Ecosystem Center, the Marine Biological Laboratory, Woods Hole, MA.

Yuille, M.J., T.B. Johnson, S.E. Arnott, and L.M. Campbell. In press. Hemimysis anomala in Lake Ontario food webs: stable isotope analysis of nearshore communities. Journal of Great Lakes Research.

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

Revision Date: 4/30/2018

Citation Information:
Kipp, R.M., A. Ricciardi, J. Larson, A. Fusaro, and T. Makled, 2019, Hemimysis anomala G.O. Sars, 1907: U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/FactSheet.aspx?SpeciesID=2627, Revision Date: 4/30/2018, Access Date: 5/20/2019

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. [2019]. Nonindigenous Aquatic Species Database. Gainesville, Florida. Accessed [5/20/2019].

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