Perccottus glenii | Amur sleeper



Legal status

Regulated invasive species of Union concern under the European Regulation on the prevention and management of the introduction and spread of invasive alien species [1143/2014].

Introduction pathways - 1

Escape from Confinement

Introduction pathways subclass - 1

Pet/aquarium species

Introduction pathways - 2

Transport Contaminant

Introduction pathways subclass - 2

Transport of habitat material

NAPRA Ireland risk assessed


Species Biology


A small fish with a maximum length of 25cm (Verreycken, 2015). Body colour is olive-green to dark green to brownish grey with a pattern of irregular patches (Baker et al., 2017). Has a large mouth, 2 dorsal fins and a rounded caudal fin (Baker et al., 2017). The males develop bright green patches over the body and a hump on the nape during spawning (Verreycken, 2015).


An opportunistic feeder with a broad diet, and the ability to alter the equilibrium in freshwater ecosystems. Impacts biodiversity reducing the species of fish in the ecosystem and the numbers of small fish (Rechulicz et al., 2015). A voracious predator, it consumes crustaceans, insects, molluscs, larval amphibians, juvenile fish and aquatic plants (Grabowska et al., 2009). Prefers waters with thick vegetation, a muddy bottom and a very slow flow (CABI, 2011). Tolerant of low oxygen conditions (Rechulicz et al., 2015) and temperatures as low as 1°C (Verreycken, 2015). Can survive desiccated or frozen conditions by hibernating in the mud (Kipichnikov, 1945 in Nehring & Steinhof, 2015). May be predated by pike (Esox lucius) or perch (Perca fluviatilis).


Males develop bright green patches over the body and a hump on the nape during spawning (Verreycken, 2015). Spawning occurs multiple times each year from April to August. The eggs are deposited on the undersides of stones or plants etc. The larvae hatch after 10-12 days. This species provides parental care for its young and the male guards the eggs, fans them with his pectoral fins to maintain a good supply of oxygen to the developing embryos and defends the nest ferociously (Grabowska et al., 2011).

Pathway and vector description

Pathways to introduction may be via the aquarium trade, when unwanted pets are dumped, as a contaminant of imported fish stocks or as escapes from aquaculture operations (Verreycken, 2015). Once established spread is by natural means downstream, which may be aided during flooding.

Mechanism of impact

Competition, Predation

Management approach

Not easily detected in the early stages of invasion (Verreycken, 2015), which makes eradication more difficult.


Verreycken (2015) recommends monitoring imported fish stocks for its presence as a stowaway.


Nehring & Steinhof (2015) suggest that ponds or fish ponds can be drained and the substrate dug out and stored on land. Once the hibernating fish have died the substrate can then be returned to the pond if desired.


Piscicides and ammonia may be effective in small closed systems but they are non-selective and expensive (Verreycken, 2015).


Control may be successfully achieved by the presence of predatory fish such as pike (Esox lucius) or perch (Perca fluviatilis).

Migration Barriers

Once present, containment can be attempted by electrical deterrent systems, air bubble curtains or chloride or pH-altered locks (Nehring & Steinhof, 2015).

Broad environment


Habitat description

Littoral zones of freshwater ponds, canals, rivers, floodplains, fish ponds, gravel pits (CABI, 2011).

Species group


Native region

Temperate Asia


World distribution(GBIF)

Introduced in the European Union in Bulgaria, Croatia, Estonia, Germany, Hungary, Lithuania, Poland, Romania, Slovakia (European Commission, 2017).

Native distribution

Far East of Eurasia, from North Korea to the Uda River basin (Russia) (Verreycken, 2015).

Temporal change

Records submitted to Data Centre in 2022

The following map is interactive. If you would prefer to view it full screen then click here.

How can you help

Report any sightings to the National Biodiversity Data Centre.

Do not purchase or dispose of in the wild.



Baker, E., A. Szczepanski, and J. Li. (2017) Perccottus glenii Dybowski, 1877: U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, and NOAA Great Lakes Aquatic Nonindigenous Species Information System, Ann Arbor, MI, , Revision Date: 2/4/2015, Site accessed 17 October 2017.

CABI. (2011). Perccottus glenii (Amur sleeper) [original text by Joanna Grabowska] [Online]. Invasive Species Compendium: Wallingford, UK: CAB International. Accessed 17 October 2017.

Caleta M., Jelic´ D., Buj I., Zanella D., Marc?ic´ Z., Mustafic´ P., Mrakovc?ic´ M. (2011) First record of the alien invasive species rotan (Perccottus glenii Dybowski, 1877) in Croatia. Journal of Applied Ichthyolgy 27 pp.146–147. Site accessed 17 October 2017.

European Commission. (2017). Invasive Alien Species of Union Concern. European Union, Luxembourg.

Grabowska J.; Grabowski M.; Pietraszewski D.; Gmur J., (2009) Non-selective predator - the versatile diet of Amur sleeper (Perccottus glenii Dybowski, 1877) in the Vistula River (Poland), a newly invaded ecosystem. Journal of Applied Ichthyology, 25(4):451-459. Site accessed 17 October 2017.

Grabowska J.; Pietraszewski D.; Przybylski M.; Tarkan A.S.; Marszal L.; Lampart-Kaluzniacka M. (2011) Life-history traits of Amur sleeper, Perccottus glenii, in the invaded Vistula River: early investment in reproduction but reduced growth rate. Hydrobiologia, 661:197-210. Site accessed 17 October 2017. 

Kirpichnikov VS (1945) Biology of Perccottus glehni Dyb. (Eleotridae) and perspectives of its use against Japanese encephalitis and malaria. Bull MOIP, Biology 50: 14v27

Kvach, Y.; Dykyy, I.; Janko, K. (2016) First record of the Chinese sleeper, Perccottus glenii Dybowski, 1877 (Actinopterygii: Odontobutidae) in the Dnieper Estuary, southern Ukraine (Black Sea drainage) BioInvasions Records 5 (4) pp. 285–290 Site accessed 17 October 2017.

Nehring, S.; Steinhof, J. (2015) First records of the invasive Amur sleeper, Perccottus glenii Dybowski, 1877 in German freshwaters: a need for realization of effective management measures to stop the invasion. BioInvasions Records 4 (3) pp. 223–232 Site accessed 17 October 2017.

Rechulicz, J., Plaska, W. & Nawrot, D. (2015) Occurrence, dispersion and habitat preferences of Amur sleeper (Perccottus glenii) in oxbow lakes of a large river and its tributary. Aquatic Ecology 49 p. 389. Site accessed 17 October 2017.

Verreycken, H. (2015) Risk analysis of the Amur sleeper Perccottus glenii, Risk analysis report of non-native organisms in Belgium, Rapporten van het Instituut voor Natuur- en Bosonderzoek 2015, INBO.R.2015.xx, updated version, Instituut voor Natuur- en Bosonderzoek, 27 p


Invasive Species in Belgium - Species information and links