Dikerogammarus villosus - Killer Shrimp


Information Last Reviewed Spring 2007


An amphipod native to the Ponto-Caspian region, Dikerogammarus villosus has recently invaded and spread throughout western Europe. Its populations have caused significant ecological disruption, including reduced biodiversity and local species extinction. Although not yet known from North America, there is major concern about the potential environmental impact of this amphipod, should it be introduced.



General Biology


Life Cycle

Habitat Characteristics






Web Sites







Phylum: Arthropoda

Class: Crustacea

Order: Amphipoda

Family: Gammaridae




General Biology



  • Bodies are laterally compressed (e.g., flattened from side to side), curled, and semi-transparent (Fig.1)

  • Body length of up to 30 mm, which is relatively large for a freshwater amphipod

  • Body consists of head, thorax, and abdomen (Fig.1)

  • Prominent features on head are two pairs of antennae, one pair of eyes, and mouthparts (Fig.1)

  • Mandibles (a type of mouthpart) of D. villosus are relatively large and powerful, thus giving it a very effective mechanism for predation

  • Thorax consists of seven segments (Fig. 1)

  • Each thoracic segment contains a pair of walking legs

  • First two pairs of walking legs are modified to assist with grasping of food

  • First four pairs of walking legs extend downwards and forwards

  • Last three pairs of walking legs extend downwards and backwards

  • Females have extra branches located on the walking legs, which create a space used to shelter and incubate eggs

  • Abdomen consists of six segments (Fig. 1)

  • Abdominal section is divided into two parts, each containing three segments

  • First set of abdominal segments contains three pairs of brush-like limbs called pleopods

  • Second set of abdominal segments contains three pairs of shorter and immobile, rod-like limbs called uropods
















Distinguishing Characteristics






Life Cycle










Habitat Characteristics


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Native Range


North American Distribution


Probable Means of Introduction

















Prevention Techniques






Bij de Vaate, A. and Klink, A. G. 1995. Dikerogammarus villosus Sowinsky (Crustacea: Gammaridae), a new immigrant in the Dutch part of the Lower Rhine. Lauterbornia 20:51-54.


Bruijs, M. C. M., Kelleher, B., van der Velde, G., and bij de Vaate, A. 2001. Oxygen consumption, temperature and salinity tolerance of the invasive amphipod Dikerogammarus villosus: Indicators of further dispersal via ballast water transport. Archiv für Hydrobiologie 152:633-646.


Devin, S., Beisel, J. N., Bachmann, V. and Moreteau, J. C. 2001. Dikerogammarus villosus (Amphipoda:Gammaridae): Another invasive species newly established in the Moselle River and French hydrosystems. Annales de Limnologie - International Journal of Limnology 37:21-27


Devin, S., Piscart, C., Beisel, J. N. and Moreteau, J. C. 2003. Life history traits of the invader Dikerogammarus villosus (Crustacea: Amphipoda) in the Moselle River, France. International Review of Hydrobiologie (In press.)


Dick, J. T. A., and Platvoet, D. 2000. Invading predatory crustacean Dikerogammarus villosus eliminates both native and exotic species. Proceedings of the Royal Society of London Biological Sciences 267(1447):977-983.


Dick, J. T. A., and Platvoet, D. 2001. Predicting future aquatic invaders; the case of Dikerogammarus villosus. Aquatic Nuisance Species Digest 4(3):25-27.


Musko, I. B. 1989. Amphipoda (Crustacea) in the littoral zone of Lake Balaton (Hungary). Qualitative and quantitative studies. Internationale Revue der gesamten Hydrobiologie 74(2):195-205.


Musko, I. B. 1994. Occurrence of Amphipoda in Hungary since 1853. Crustaceana 66(2):144-152.


Sporka, F. 1999. First record of Dikerogammarus villosus (Amphipoda, Gammaridae) and Jaera istri (Isopoda, Asselota) from the Slovak-Hungarian part of the Danube river. Biologia (Bratislava) 54(5):538.


Van den Brink, F. W. B., Van der Velde, G. and Bij de Vaate, A. 1991 Amphipod invasion on the Rhine. Nature 352:576


Van der Velde, G., Rajagopal, S., Kelleher, B., Muskó, I. B. and Bij de Vaate, A. 2000. Ecological impact of crustacean invaders: General considerations and examples from the Rhine River. Crustacean Issues 12:3-33.




Web Sites



Selective Pollination - Donald Forsha Jones (1928) Chapter 7



Guardian Unlimited - Pink Peril threatens native species in Britain’s rivers



NOAA, Great Lakes Environmental Research Laboratory



This report was prepared by Danielle M. Crosier and Daniel P. Molloy (New York State Museum) with assistance from Abraham bij de Vaate (Institute for Inland Water Management & Waste Water Treatment - The Netherlands) and Simon Devin (Université de Metz - France).