Invasion HistoryFirst Non-native North American Tidal Record: 1999
First Non-native West Coast Tidal Record:
First Non-native East/Gulf Coast Tidal Record: 1999
General Invasion History:
Echinogammarus ischnus is native to the Black and Caspian Sea basins and the surrounding inflowing rivers (Dediu 1980; Cristescu et al. 2004). It is known to survive and reproduce in salinities of 0 to18 PSU (Mordukhai-Boltovskoi 1964; Dediu 1980). Black Sea and Caspian populations show considerable genetic divergence (Cristescu et al. 2004). The development of canal systems permitted its spread into river systems of the Baltic and North Sea drainages (Jazdsewski 1980; Bij de Vaate et al. 2002; Konapacka 2002). By the 1990s, it reached the Elbe, Weser, and Ems rivers and the Rhine Delta (Bij de Vaate et al. 2002). In 1994 and 1995, E. ischnus was collected in North America in the Lake Erie and the Detroit River (Witt et al. 1995; Dermott et al. 1998). By 2009, its range extended from Duluth Harbor on Lake Superior (Trebitz et al. 2012) to Berthier-sur-Mer, about 40 km downstream of Quebec City, in the St. Lawrence River estuary (Radulovici et al. 2009). It has also colonized the upper Mississippi and lower Ohio rivers (Grigorovich et al. 2008), the Finger Lakes and Oneida Lake, in the interior of New York State (Cooper et al. 2012; USGS Nonindigenous Aquatic Species Program 2016), probably by canals, or possibly, trailered boats. Echinogammarus ischnus is a possible future invader in the Hudson River estuary, through the New York State Barge Canal, and could be transported by ballast water to other East Coast estuaries. Transport from the Great Lakes and upper Mississippi basin on trailered boats or fishing gear is also possible.
North American Invasion History:
Invasion History on the East Coast:
In 1994 and 1995, E. ischnus was collected in North America in the Lake Erie and the Detroit River (Witt et al. 1995; Dermott et al. 1998; USGS Nonindigenous Aquatic Species Program 2016). By 1998, it was found in Lake Huron, Lake Michigan, Lake Ontario and the upper St. Lawrence River (Dermott 1998; Nalepa 2001; USGS Nonindigenous Aquatic Species Program 2016). It was collected in Thunder Bay, Lake Superior in 2003 (Grigorevich 2005), and by 2005, it was found in Duluth-Superior Harbor (Trebitz et al. 2010). By 1999, it was collected in the St. Lawrence River estuary at Quebec City (Vanderploeg et al. 2002). In samples collected between 2000 and 2008, at Berthier-sur-Mer, about 40 km downstream of Quebec City, E. ischnus was identified by DNA barcoding (Radulovici et al. 2009).
Echinogammarus ischnus has colonized waterbodies adjacent to the Great Lakes, including the upper Mississippi-Ohio basin, and the Finger Lakes and Oneida Lakes in New York (NY). In 2004, E. ischnus was found at five locations on the upper Mississippi between River Miles 477 and 835, and at two sites on the Ohio River, at miles 471 and 584. By 2006, its distribution on the middle reaches of the two rivers was continuous. It has been recorded from sites in Iowa, Illinois, Kentucky, and Ohio. By 2012, it was extensively distributed in the Finger Lakes system in NY (USGS Nonindigenous Aquatic Species Program 2016). It was collected in Oneida Lake, NY in 2001 and is abundant there. The Finger and Oneida Lakes are connected to the Great Lakes by the New York State Barge (Erie) Canal (Cooper et al. 2012). Transport from the Great Lakes on barge fouling or on trailered boats is possible (Grigorovich et al. 2008; Cooper et al. 2012). Echinogammarus ischnus is expected to reach the Hudson River though the canal, but has not been reported yet.
Invasion History Elsewhere in the World:
Echinogammarus ischnus was first found outside the Ponto-Caspian basin in the Vistula River, Poland, in 1928, which it reached from the Dnieper River, a Black Sea tributary, via the Pripet-Bug canal (Jazdsewski 1980; Bij de Vaate et al. 2002; Konapacka 2002). In 1967-1971, it was dominant in the Vistula Lagoon, but it was absent in surveys in 1998-2000 and 2007, having been replaced by Dikerogammarus haemobaphes and Pontogammarus robustoides (Surowiec and Dobrzycka-Krahel 2008). It reached the Neman River, Lithuania by 1960 and by 1964, colonized the Curonian Lagoon (Latvia-Lithuania) (Olenin and Leppakoski 2008), probably also by canals linked to the Pripyat-Bug Canal (Bij de Vaate et al. 2002). Echinogammarus ischnus spread west, reaching Germany through canals joining the Elbe, Weser, and Ems rivers in the 1970s, the Rhine River by 1989, and the Rhine estuary by 1991 (Bij de Vaate et al. 2002). In 2008-2009, it was found in the Rhine, Meuse, and Seine River basins in France (Labat et al. 2011).
The body of Echinogammarus ischnus is laterally compressed, and lacks dorsal teeth. This species has strong sexual dimorphism, with the male longer than the female, and the male having a densely setose Antenna 2. It has a short, triangular rostrum. The eyes are kidney-shaped and twice as long as wide. Antennae 1 and 2 are roughly equal in length. Antenna 1 has a prominent accessory flagellum, with 17-22 segments. Antenna 2 has dense, long, curly setae in males, and moderate, shorter setae in females. Gnathopod 2 is larger than Gnathopod 1. The palms of the gnathopods are oblique and the dactyls are slender. The basipodite of pereiopod V is distally narrowed, without a postero-dorsal projection. Uropod 3 has a small scale-like inner ramus, less than half the length of the outer ramus. The exopod is relatively long, encircled by up to five rows of setae and tipped with a short spine. The telson is cleft to the base with two dorsal and three apical spines on each lobe. Males are 6-15 mm and females are 5-13 mm in size. This description is based on Köhn and Waterstraat 1990; Witt et al. 1997; and Crosier and Molloy 2003.
Chaetogammarus tenellus (G. O. Sars, 1914)
Potentially Misidentified Species
Ponto-Caspian Fresh-brackish-water amphipod, introduced to the Gulf of Finland, Russia, and Lithuania (Arbaciauskas 2005; Berezina et al. 2011).
Native, freshwater, Ontario to Chesapeake Bay and Missouri (Bousfield 1973; Grigorovich et al. 2009).
Freshwater-Estuarine species, Native from the Gulf of St. Lawrence to Florida (Bousfield 1973). Introduced to the Great lakes-St. Lawrence estuary from Lake Superior to the inner estuary, and to the upper Mississippi (Grigorovich et al. 2005; Grigorovich et al. 2009). This amphipod is also widely introduced in Europe (Grabowski 2009).
Marine species, native to the North Atlantic, Newfoundland to Long Island Sound (Bousfield 1973). Initial ID from St. Lawrence River, Quebec, but DNA barcoding identified animals as E. ischnus (Radulovici et al. 2009).
Echinogammarus ischnus has separate sexes, the young are brooded, and development is direct (Bousfield 1973). The animals mature at ~4.8 mm (Crosier and Molloy 2003). This amphipod bears up to 20 eggs, depending on body size (Kohn and Waterstraat 1990). They mature in 44-65 days over the temperature range of 20-24°C, and have 2-3 generations per year (Kohn and Waterstraat 1990; Crosier and Molloy 2003).
Echinogammarus ischnus tolerates a wide temperature range, from near-freezing to above 30°C (Dediu 1980). In its native range, it occurs in the Caspian Sea and Black Sea estuaries (Mordukhai-Boltovskoi 1964; Dediu 1980). It ranges widely into freshwater, but is sensitive to water of low ionic content (conductivity). Growth and survival was reduced at low conductivities (108 µS/cm), after heavy river flow, and better at higher conductivity (300 µS/cm), reflecting its evolution in saline waters (Kestup et al. 2010). In tests of simulated ballast water exchange, a small proportion (~1-5%) of E. ischnus survive after exposure for 48 hours to a salinity of 30 PSU. In its introduced range, E. ischnus is abundant on rocky and cobble shores, but especially favors clumps of Zebra and Quagga Mussel (Dreissena) shells. It is not strongly associated with vegetation (Dermott et al. 1998; Nalepa 2001) and may be more vulnerable to fish predation in vegetation than the North American native Gammarus fasciatus (Gonalez and Burkett 2004). The Dreissena invasion in Europe and the Great Lakes-St. Lawrence River may have facilitated the spread of E. ischnus by providing shelter from predation (Kohn and Waterstraat 1990; Kang et al. 2007). In the St. Lawrence River, it was positively correlated with dreissenid mussels, coarse gravel sediment, and increasing current (Palmer and Ricciardi 2004).
Echinogammarus ischnus is an omnivore, feeding on algae, aquatic plants, and occasional invertebrates (Barnes 1983; Krisp and Maier 2005), including other amphipods, such as G. fasciatus (Kestrup and Ricciardi 2009). However, in a comparison of adults and juveniles of five introduced and one native gammarid amphipod in Poland, had a relatively low trophic level (Bacela-Spychalska et al. 2013). Aside from Gammarus fasciatus in North America, and several Ponto-Caspian amphipods in Europe, fishes are the major predators of E. ischnus (Palmer et al. 2005). In the St. Lawrence River, a fungus of the Saprolegniaceae infects E. ischnus, and causes greater mortality to it, than to G. fasciatus, facilitating the coexistence of the two species (Kestrup et al. 2011).
detritus, algae, invertebrates
|General Habitat||Nontidal Freshwater||None|
|General Habitat||Grass Bed||None|
|General Habitat||Coarse Woody Debris||None|
|General Habitat||Marinas & Docks||None|
|Salinity Range||Limnetic||0-0.5 PSU|
|Salinity Range||Oligohaline||0.5-5 PSU|
|Salinity Range||Mesohaline||5-18 PSU|
Tolerances and Life History Parameters
|Minimum Temperature (ºC)||0||Dediu 1980|
|Maximum Temperature (ºC)||30||Dediu 1980|
|Minimum Salinity (‰)||0||None|
|Maximum Salinity (‰)||18||Mordukhai-Boltovskoi 1964; Dediu 1980)|
|Maximum Length (mm)||15||Males, Females 13 mm, Europe (Crosier and Malloy 2003); Lake Kummerow, Germany. Females reached 8 mm (Kohn et al. 1990; 9.1 mm adult male, 5.3 adult female (Witt et al.1997, Detroit River, Ontario)|
|Broad Temperature Range||None||Cold temperate-Warm temperate|
|Broad Salinity Range||None||Nontidal Limnetic-Mesohaline|
General ImpactsEchinogammarus ischnus has replaced the native Gammarus fasciatus (Dermott et al. 1998) at many locations in the Great Lakes and St. Lawrence River through predation and competition, but this may also be due to selective predation by the Round Goby (Neogobius melanostomus) (Van Overdijk et al. 2003; Kestrup et al. 2011a). However, G. fasciatus persists in many locations, with competition mediated by environmental factors. Low conductivity, due to spring river flows, reduces the competitiveness of E. ischnus, as does a fungus, to which E. ischnus is more vulnerable (Kestrup and Ricciardi 2009; Kestrup et al. 2011b).
|GL-III||Lake Ontario||Ecological Impact||Competition|
|Echinogammarus ischnus has largely replaced the native Gammarus fasciatus (Dermott et al. 1998), in the upper St. Lawrence River, but this may be due to selective predation by the Round Goby [Neogobius melanostomus (Overdijk et al. 2003)], or due to abiotic factors such as calcium concentration and conductivity (Kestrup and Ricciardi 2009).|
|In the Vistula Lagoon, E. ischnus was classified as having a moderate level of community impacts (Zaiko et al. 2011).|
|GL-III||Lake Ontario||Ecological Impact||Predation|
|In the upper St. Lawrence River, Echinogammarus ischnus and Gammarus fasciatus are mutual predators, with E. ischnus prevailing at higher conductivity, and declining due to predation duiring periods of lower conductivity and heavy spring riverflows (Kestrup and Ricciardi 2009).|
Regional Distribution Map
|Bioregion||Region Name||Year||Invasion Status||Population Status|
|GL-I||Lakes Huron, Superior and Michigan||1996||Def||Estab|
ReferencesAarnio, Katri; Törnroos, Anna; Björklund, Charlotta; Bonsdorff, Erik (2015) Food web positioning of a recent coloniser: the North American Harris mud crab Rhithropanopeus harrisii (Gould, 1841) in the northern Baltic Sea, Aquatic Invasions 10: In press
Bacela-Spychalska, Karolina; Van Der Velde, Gerard (2013) There is more than one ‘killer shrimp’: trophic positions and predatory abilities of invasive amphipods of Ponto-Caspian origin, Freshwater Biology 58: 730-741
Berezina, Nadezhda A.; Petryashev, Viktor V.; Razinskovas, Arturas; Lesutiene, Jurate (2011) In the wrong place- Alien marine crustaceans: Distribution, biology, impacts, Springer, Dordrecht, Netherlands. Pp. 301-322
Bij de Vaate,A.; Jazdzewski, K.; Ketelaars, H.A.M; Gollasch, S.; van der Velde, G. (2002) Geographical patterns in range extension of Ponto-Caspian macroinvertebrate species in Europe., Canadian Journal of Fisheries and Aquatic Science 59: 1159-1174
Cooper, John E.; Wallquist., Elin; Holeck, Kristen T.; Hoffman, Catharine E.; Mills, Edward L.; Mayer, Christine M. (2012) Density and distribution of amphipods in Oneida Lake, New York, after the introduction of the exotic amphipod Echinogammarus ischnus, Northeastern Naturalist 19(2): 249-266
Cristescu, M. E. A.; Witt, J. D. S.; Grigorovich, I. A.; Hebert, P. D. N.; MacIsaac, H. J. (2004) Dispersal of the Ponto-Caspian amphipod Echinogammarus ischnus: invasion waves from the Pleistocene to the present., Heredity 32: 197-203
Crosier, Danielle M. ; Molloy, Daniel P.; Grigorovich, Igor A. (2003) <missing title>, U.S. Army Corps of Engineers, <missing place>. Pp. 1-7
Dediu, I. I. (1980) <missing title>, Shtiintsa, Kishinev, Moldova. Pp. <missing location>
Dermott, Ronald, Witt, Jonathan, Um, Young M., Gonzalez, Maria (1998) Distribution of the Ponto-Caspian amphipod Echinogammarus ischnus in the Great Lakes and replacement of native Gammarus fasciatus., Journal of Great Lakes Research 24(3): 442-452
Devin, Simon; Beisel, Jean-Nicolas (2006) Biological and ecological characteristics of invasive species: a gammarid study., Biological Invasions 9: 13-24
Dobson, Michael (2012) <missing title>, Freshwater Biological Association, Far Sawrey, Ambleside, Cumbria, England. Pp. <missing location>
Ellis, Sandra; MacIsaac, Hugh J . (2009) Salinity tolerance of Great Lakes invaders., Freshwater Biology 54(1): 77-89
Gallardo, Belinda; Aldridge, David C. (2013) Priority setting for invasive species management: risk assessment of Ponto-Caspian invasive species into Great Britain, Ecological Applications 23(2): 352–364 2013
Gimenez, Lucas H.; Rivera, Reinaldo J.; Brante, Antonio (2022) One step ahead of sea anemone invasions with ecological niche modeling: potential distributions and niche dynamics of three successful invasive species, Marine Ecologicy Progress Series 690: 83–95
González, María J.; Burkart, Greta A. (2004) Effects of food type, habitat, and fish predation on the relative abundance of two amphipod species, Gammarus fasciatus and Echinogammarus ischnus, Journal of Great Lakes Research 30(1): 100-113
Grabowski, Michal; Bacela, Karolina; Konopacka, Alicja (2007) How to be an invasive gammarid (Amphipoda: Gammaroidea): Comparison of life history traits., Hydrobiologia 590: 75-84
Grabowski, Michal; Bacela, Karolina; Konopacka, Alicja;Jazdzewski, Krzysztof (2009) Salinity-related distribution of alien amphipods in rivers provides refugia for native species, Biological Invasions 11: 2107-2117
Grigorovich, Igor A..; Kang, Misung, Ciborowski, Jan J. H. (2005) Colonization of the Laurentian Great Lakes by the amphipod Gammarus tigrinus, a native of the North American Atlantic coast., Journal of Great Lakes Research 31: 333-345
Grigorovich, Igor A.; Angradi, Ted R.; Emery, Erich B.; Wooten, Matthew S. (2008) Invasion of the upper Mississippi River system by saltwater amphipods, Archiv fur Hydrobiologie 173(1): 67-77
Grigorovich, Igor A; Korniushin, Alexei V.; Gray, Derek K.; Duggan, Ian C.; Colautti, Robert I.; MacIsaac, Hugh J. (2003) Lake Superior: an invasion coldspot?, Hydrobiologia 499: 191-210
Holopainen, Reetta; Lehtiniemi, Maiju; Meier, H. E. Markus; Albertsson, Jan; Gorokhova, Elena; Kotta, Jonne; Viitasalo, Markku (2016) Impacts of changing climate on the non-indigenous invertebrates in the northern Baltic Sea by end of the twenty-first century, Biological Invasions Published online: <missing location>
Jazdzewsi, Krzysztof; Konopacka, Alicja (2002) Invasive aquatic species of Europe: Distribution, impacts, and management., Kluwer Academic Publishers, Dordrecht. Pp. 383-398
Jazdzewski, Kryzysztof; Grabowski, Michal (2011) In the wrong place- Alien marine crustaceans: Distribution, biology, impacts, Springer, Dordrecht, Netherlands. Pp. 323-344
Jazdzewski, Krzysztof (1980) Range extensions of some gammaridean species in European inland waters caused by human activity., Crustaceana Suppl. 6: 84-107
Jazdzewski, Krzysztof; Grabowski, Michal; Konopacka, Alicja; (2004) Recent drastic changes in the gammarid fauna (Crustacea, Amphipoda) of the Vistula River deltaic system in Poland caused by alien invaders., Diversity and Distributions 10: 81-87
Jazdzewski, Krzysztof; Konopacka, Alicja; Grabowski, Michal; (2005) Native and alien malacostracan Crustacea along the Polish Baltic Sea coast In the twentieth century., Oceanological and Hydrobiological Studies 34(Suppl. 1.): 175-193
Kang, Misun; Ciborowski, Jan J. H.; Johnson, Lucinda B. (2007) The influence of anthropogenic disturbance and environmental suitability on the distribution of the nonindigenous amphipod, Echinogammarus ischnus, at Laurentian Great Lakes coastal margins, Journal of Great Lakes Research 33(Special Issue 3): 198-210
Kestrup, Asa M.; Ricciardi, Anthony (2009a) Environmental heterogeneity limits the local dominance of an invasive freshwater crustacean, Biological Invasions 11: 2095-2105
Kestrup, Asa M.; Dick, Jaimie T. A.; Ricciardi, Anthony (2011a) Interactions between invasive and native crustaceans: differential functional responses of intraguild predators towards juvenile hetero-specifics, Biological Invasions 13: 731-737
Kestrup, Asa M.; Thomas, Sara H. Rensburg, Karla van; Ricciardi, Anthony; Duffy, Meghan A. (2011b) Differential infection of exotic and native freshwater amphipods by a parasitic water mold in the St. Lawrence River, Biological Invasions 13: 769-779
Kestrup, Åsa; Ricciardi, Anthony (2009b) Are interactions among Ponto-Caspian invaders driving amphipod species replacement in the St. Lawrence River?, Journal of Great Lakes Research 35: 392-398
Kestrup, Åsa; Ricciardi, Anthony (2010) Influence of conductivity on life history traits of exotic and native amphipods in the St. Lawrence River, Fundamental and Applied Limnology 176(3): 249-262
Kley, Axel; Maier, Gerhard (2003) Life history characteristics of the invasive freshwater gammarids Dikerogammarus villosus and Echinogammarus ischnus in the river Main and the Main-Donau canal., Archiv fur Hydrobiologie 156: 457-469
Kobak, Jaros?aw; Rachalewski, Micha?; Bacela-Spychalska, Karolina (2016) Conquerors or exiles? Impact of interference competition among invasive Ponto-Caspian gammarideans on their dispersal rates, Biological Invasions Published online: <missing location>
Kohn, Jorg ; Waterstraat, Arno (1990) The amphipod fauna of Lake Kummerow (Mecklenburg, German Democratic Republic) with reference to Echinogammarus ischnus Stebbing, 1899, Crustaceana 58(1): 74-82
Krisp, Holger; Maier, Gerhard (2005) Consumption of macroinvertebrates by invasive and native gammarids: a comparison, Journal of Limnology 64(1): 55-59
Labat, Frédéric; Piscart, Christophe; Fontan, Bruno (2011) First records, pathways and distributions of four new Ponto-Caspian amphipods in France, Limnologica 41: 290-295
Leppakoski, Erkki; Olenin, Sergei (2000) Non-native species and rates of spread: lessons from the brackish Baltic Sea., Biological Invasions 2: 151-163
Mordukhai-Boltovskoi, Ph. D. (1964) Caspian fauna beyond the Caspian Sea, Internationale Revue der Gesamten Hydrobiologie 49(1): 139-170
Mordukhay-Boltovskoi, Ph. D. (1964) Caspian fauna in fresh waters outside the Ponto Caspian basin, Hydrobiologia 13(1-2): 159-164
Nalepa, Thomas F. and 6 authors (2001) First finding of the amphipod Echinogammarus ischnus and the mussel Dreissena bugensis in Lake Michigan, Journal of Great Lakes Research 27(3): 384-391
2000-2016 Inventory of Baltic Sea alien species. http://www.ku.lt/nemo/species.htm
Paavola, Marjo; Olenin, Sergei; Leppakoski, Erkki (2005) Are invasive species most successful in habits of low native species richness across European brackish water seas?, Estuarine Coastal and Shelf Science 64: 738-750
Palmer, M.; Ricciardi, E. A. (2004) Physical factors affecting the relative abundance of native and invasive amphipods in the St. Lawrence River, Canadian Journal of Zoology 82: 1886-1893
Palmer, M.E.; Ricciardi, Anthony (2005) Community interactions affecting the relative abundances of native and invasive amphipods in the St. Lawrence River., Canadian Journal of Fisheries and Aquatic Sciences 62: 1111-1118
Pennuto, Christopher; Keppler, Dawn (2008) Short-term predator avoidance behavior by invasive and native amphipods in the Great Lakes, Aquatic Ecology 42: 629-641
Radulovici , Adriana E.; Sainte-Marie, Bernard; Dufresne, France (2009) DNA barcoding of marine crustaceans from the Estuary and Gulf of St Lawrence: a regional-scale approach, Molecular Ecology Resources 9(Suppl. 1): 181-187
Ricciardi, Anthony (2001) Facilitative interactions among aquatic invaders: is an "invasional meltdown" occurring in the Great Lakes?, Canadian Journal of Fisheries and Aquatic Sciences 58: 2513-2525
Ricciardi, Anthony; MacIsaac, Hugh J. (2000) Recent mass invasion of the North American Great Lakes by Ponto-Caspian species., Trends in Ecology and Evolution 15(2): 62-65
Takhteev, V. V.; Berezina, N. A.; Sidorov, D. A. (2015) Checklist of the Amphipoda (Crustacea) from continental waters of Russia, with data on alien species, Arthropoda Selecta 24(3): 335-370
Trebitz, Anett S. and 5 authors (2010) Status of non-indigenous benthic invertebrates in the Duluth-Superior Harbor and the role of sampling methods in their detection, Journal of Great Lakes Research 36: 747-756
2003-2022 Nonindigenous Aquatic Species Database. Gainesville, FL. http://nas.er.usgs.gov
van den Brink, F.W.B.; Paffen, B.G.P.; Oosterbroek, F.M.J.; van der Velde, G. (1991) Immigration of Echinogammarus (Crustacea: Amphipoda) into the Netherlands via the lower Rhine., Bulletin Zoologisch Museum Universiteit van Amsterdam 13(14): 167-169
Van der Velde, Gerard, Rajagopal, Sanjeevi, Kelleher, Barry, Musko, Ilona B., Bij de Vaate, Abraham (1999) The biodiversity crisis and Crustacea: proceedings of the Fourth International Crustacean Conference, In: (Eds.) . , Rotterdam. Pp. 3-33
Van Overdijk, Colin D. A.; Grigorovich, Igor A. ; Mabee, Tracy; Ray, William J.; Ciborowski , Jan J. H. Macisaac, Hugh J. (2003) Microhabitat selection by the invasive amphipod Echinogammarus ischnus and native Gammarus fasciatus in laboratory experiments and in Lake Erie, Freshwater Biology 48: 567-578
van Riel, M. C.; van der Velde, G.; bij de Vaate, A. (2009) Interference competition between alien invasive gammaridean species, Biological Invasions 11: 2119-2132
Vanderploeg, Henry A. and 7 authors (2002) Dispersal and emerging ecological impacts of Ponto-Caspian species in the Laurentian Great Lakes, Canadian Journal of Fisheries and Aquatic Science 59: 1209-1228
Wijnhoven, S.; Van Riel, M.C./; van der Velde, G. (2003) Exotic and indigenous freshwater gammarid species: physiological tolerance to water temperature in relation to ionic content of the water., Aquatic Ecology 37: 151-158
Witt, Jonathan D. S.; Hebert, Paul D. N.; Morton, William B. (1997) Echinogammarus ischnus: another crustacean invader in the Laurentian Great Lakes system., Canadian Journal of Fisheries and Aquatic Sciences 54: 264-268
Wouters, Karel (2002) On the distribution of alien non-marine and estuarine macro-crustaceans in Belgium., Bulletin Van Het Koninklin Instituut Voor Naturwetenschappen, Biologie. 17: 119-129
Zaiko, Anastasija; Lehtiniemi, Maiju; Narscius, Aleksas; Olenin, Sergej (2011) Assessment of bioinvasion impacts on a regional scale: a comparative approach, Biological Invasions 13: 1739-1765