Varroa mite	Status LU: established. 1st record: 1985.
	Varroamilb	Status Eur.: established.
	n/a	RA: ISEIA: A3, Black List. Harmonia+: n/a.
	Varroamilbe	Wikipedia: | Wikispecies: | CABI
	Varroamijt	Back to the list of invertebrates

Brief description

Varroa destructor Anderson & Trueman, 2000 is an external parasitic mite that attack and feeds on the honey bees Apis cerana and Apis mellifera. The disease caused by the mites is called varroosis. The Varroa mite can only reproduce in a honey bee colony. It attaches to the body of the bee and weakens the bee by sucking fat bodies. The species is a vector for at least five debilitating bee viruses, including RNA viruses such as the deformed wing virus (DWV). A significant mite infestation leads to the death of a honey bee colony, usually in the late autumn through early spring. The Varroa mite is the parasite with possibly the most pronounced economic impact on the beekeeping industry. Varroa is considered to be one of multiple stress factors contributing to the higher levels of bee losses around the world.

The adult female mite is reddish-brown in color, while the male is white. Varroa mites are flat, having a button shape. They are 1–1.8 mm long and 1.5–2 mm wide, and have eight legs. Mites reproduce on a 10-day cycle (Wikipedia contributors 2020).

Status and distribution in Luxembourg

Varroa destructor Anderson & Trueman, 2000 was observed for the first time in Luxembourg in 1985 (Meisch 1986). Claude Meisch recalls: “At that time it was a delicate matter, no beekeeper wanted to admit that he had the parasite in his hives. I remember well that I was the first to admit in meetings that I had found Varroa in my hives. Probably Varroa was already widespread in the whole country at that time” (Meisch 2018).

In the 1980s, Varroa spread throughout the country and is nowadays present in every beehive.

There is no distribution map available because no data has been entered into the Recorder-Lux database so far (MNHNL, iNaturalist & GBIF 2019).

Risk assessment

ISEIA protocol

A3 (3+3+3+3) = Black List (Ries et al. 2017: 68).

Harmonia+ protocol

Not assessed yet.

Worldwide distribution

Bibliography

• CABI, 2008. Varroa destructor Anderson & Trueman, 2000 [original text by Claire Beverley]. In: Invasive Species Compendium. Wallingford, UK: CAB International. URL: www.cabi.org/isc [accessed 2019-11-26]
• MNHNL, iNaturalist & GBIF, 2019. MNHNL-mdata, online portal combining species observation from Recorder-Lux, iNaturalist and GBIF. National Museum of Natural History, Luxembourg. URL: https://mdata.mnhn.lu [Accessed 2019-10-24]
• Meisch, C., 1986. Die Varroamilbe. Geschichte der Ausbreitung, Portrait und Biologie. Pp. 174-177 in: Livre d’or du centenaire 1886-1986. Fédération des unions d’apiculteurs du grand-duché de Luxembourg.
• Meisch, C., 2018. Personal communication to Lucie Lentz during Summer 2018.
• Ries, C., A. Arendt, C. Braunert, S. Christian, A. Dohet, A. Frantz, G. Geimer, M. Hellers, J. A. Massard, X. Mestdagh, R. Proess, N. Schneider & M. Pfeiffenschneider, 2017. Environmental impact assessment and black, watch and alert list classification after the ISEIA Protocol of invertebrates in Luxembourg. Bull. Soc. Nat. luxemb. 119: 63-70. [PDF 360 KB]
• Wikipedia contributors, 2020. ‘Varroa destructor’, Wikipedia, The Free Encyclopedia, 19 February 2020, 15:24 UTC, <https://en.wikipedia.org/w/index.php?title=Varroa_destructor&oldid=941598994> [accessed 2020-03-13]

 Page content last updated on 2026-09-22. Last proofread by Caroline Grounds on 2019-12-12.

	n/a	Status LU: established. 1st record: 2009.
	Roude Schneider	Status Eur.: established.
	n/a	RA: ISEIA: B3, Watch List. Harmonia+: n/a.
	Apenninen-Kanker	Wikipedia:   | Wikispecies: n/a (2020) | CABI
	Rode hooiwagen	Back to the list of invertebrates

Brief description

Opilio canestrinii is a species of harvestman. Males reach a body length up to 6 mm, females up to 8 mm. While males are yellowish brown to reddish, females are lighter. Males have dark legs, but yellow coxae and “knees”; the legs of females show alternately light and dark rings. The backs of females sport a dark, saddle-like pattern with a light longitudinal stripe in the middle. Adults can be found from June to December.

O. canestrinii probably originates from Italy, but has invaded Central Europe since the late 1970, and has since almost everywhere replaced the similar O. parietinus. It is most often found on house walls (Wikipedia contributors 2019).

Status and distribution in Luxembourg

The first documented occurrence of the species in Luxembourg dates from 2009. It was found by C. Muster on 20th August 2009 in Fort Berlaimont (Municipality of Luxembourg).

Opilio canestrinii is the second most common harvestman in Luxembourg and can be found in every region of the country.

Opilio canestrinii colonises a number of open habitats independently of their moisture levels. It is very successful in man-made landscapes, even in bigger cities. It is a strong competitor to native species and seems able to displace or even replace them. There are indicators that the similar Opilio parietinus, traditionally a common species on house walls, has nearly vanished, just a few years after the arrival of O. canestrinii.

Several sources describe this harvestman as a typical species of urban areas. In Luxembourg however, the data provided from different projects show evidence that the species occurs in great numbers and important percentages even in close-to-nature areas. Since the 1960s, O. canestrinii has spread extremely quickly northwards through Europe and has become a more or less common species in their new areas.

Risk assessment

ISEIA protocol

B3 (3+2+3+1) = Watch List (Ries et al. 2017: 68).

Harmonia+ protocol

Not assessed yet.

Worldwide distribution

Bibliography

• CABI, 2019. Opilio canestrinii. In: Invasive Species Compendium. Wallingford, UK: CAB International. URL: www.cabi.org/isc [accessed 2020-03-05]
• GBIF, 2020. Opilio canestrinii in GBIF Secretariat (2019). GBIF Backbone Taxonomy. Checklist dataset https://doi.org/10.15468/39omei [accessed 2020-03-05]
• MNHNL, iNaturalist & GBIF, 2020. Opilio canestrinii in MNHNL-mdata, online portal combining species observation from Recorder-Lux, iNaturalist and GBIF. National Museum of Natural History, Luxembourg. URL: https://mdata.mnhn.lu [Accessed 2020-03-05]
• Muster, C. & M. Meyer, 2014. Verbreitungsatlas der Weberknechte des Großherzogtums Luxemburg. Ferrantia 70. Musée national d’histoire naturelle, Luxembourg, 112 S. (PDF 3.8 MB)
• Ries, C., A. Arendt, C. Braunert, S. Christian, A. Dohet, A. Frantz, G. Geimer, M. Hellers, J. A. Massard, X. Mestdagh, R. Proess, N. Schneider & M. Pfeiffenschneider, 2017. Environmental impact assessment and black, watch and alert list classification after the ISEIA Protocol of invertebrates in Luxembourg. Bull. Soc. Nat. luxemb. 119: 63-70. [PDF 360 KB]
• Weber, D. (Hrsg.), 2014. Die Höhlenfauna Luxemburgs. Ferrantia 69. Musée national d’histoire naturelle Luxembourg, 408 pp. + CD-Rom (PDF 19 MB)
• Wikipedia contributors, 2019. Opilio canestrinii. Wikipedia, The Free Encyclopedia, 17 January 2019, 10:39 UTC, &lt;https://en.wikipedia.org/w/index.php?title=Opilio_canestrinii&amp;oldid=878854172&gt; [accessed 2020-03-05]

 Page content last updated on 2026-09-22. Last proofread by Caroline Grounds on 2019-12-10.

	n/a	Status LU: established. 1st record: ?
	n/a	Status Eur.: established. 1st record: ~2000 (NL).
	n/a	RA: ISEIA: C2. Harmonia+: n/a.
	Namenloser Rückenkanker	Wikipedia: | Wikispecies: n/a (2020)
	n/a	Back to the list of invertebrates

Brief description

Since probably 2000, a completely unknown harvestman started its quick expansion through Central Europe. The species could be classified in the genus Leiobunum, but is different from other European species. It has been named provisionally as Leiobunum sp. (sensu Wijnhoven et al. 2007). It is assumed that it arrived with ships from overseas, probably reaching the Netherlands first. It is still unknown exactly where it came from (Wijnhoven et al. 2007).

The area of origin is unknown to date, since about 2000 the species has probably spread from the Netherlands into Western Germany on both sides of the Rhine valley to Switzerland and Vorarlberg (Wijnhoven et al. 2007), in the meantime also to Schleswig-Holstein (Staudt 2012).

Habitat: Primarily possibly a rock dweller, in Europe in habitats of anthropogenic origin: industrial wastelands, ruins and house walls (Wijnhoven et al. 2007). Leiobunum sp. generally tend to cluster together during the day. This behaviour is even more pronounced in the species in question. Mass aggregations of several hundreds of individuals have been observed. Many observations show that in spite of its high reproduction rate this “new” Leiobunum sp. seems to coexist well with indigenous species and integrates in the native fauna without great damage. But surely great colonies of the species compete for food with other similar predators.

Status and distribution in Luxembourg

No records of Leiobunum sp. (sensu Wijnhoven et al. 2007) are present in the MNHNL-mdata portal (MNHNL, iNaturalist & GBIF, 2020).

Already widespread in the Gutland, Leiobunum sp. still largely absent in the Ösling (Muster & Meyer 2014: 79). In Luxembourg exclusively synanthropic, larger aggregations have so far only been observed on industrial ruins in the Minette area, in small numbers of individuals in many places on average house walls.

Remarks (Muster & Meyer 2014: 82): Due to the occurrence of mass aggregations with > 1000 specimens the species became the focus of media and sensation-hungry public after 2007. Suddenly, weavers were the focus of exhibitions, local publications, radio and television broadcasts. Wijnhoven et al. (2007) also warned urgently of an imminent invasion of unprecedented proportions and possible dramatic effects on the native opilionid fauna. A few years after this initial uncertainty, the situation is now much more relaxed. Despite the now widespread distribution in Luxembourg, no mass increases could be registered. Only in the former Goodyear test site near Esch-sur-Alzette and at industrial ruins near Rodange larger colonies of 100-200 specimens were sighted. Otherwise only smaller groups of maximum 10 specimens were observed, often only single specimens. It was noticeable that often only one dwelling house per small village was inhabited, while other similar houses remained unoccupied. In this context, observations from the Ruhr area seem interesting, according to which the animals show a preference for calcareous surfaces rich in structure (Toss 2010). The effects on other weaver’s apprentice species are also likely to be less severe than originally assumed. Leiobunum rotundum is often found at or even within aggregations of the Nameless Spine Anchor, while they even seem to evade Dicranopalpus ramosus (Wijnhoven 2011).

Risk assessment

ISEIA protocol

C2 (2+2+2+1) (Ries et al. 2017: 68).

Harmonia+ protocol

Not assessed yet.

Bibliography

• MNHNL, iNaturalist & GBIF, 2020. MNHNL-mdata, online portal combining species observation from Recorder-Lux, iNaturalist and GBIF. National Museum of Natural History, Luxembourg. URL: https://mdata.mnhn.lu [Accessed 2020-03-05]
• Muster, C. & M. Meyer, 2014. Verbreitungsatlas der Weberknechte des Großherzogtums Luxemburg, Ferrantia 70. Musée national d’histoire naturelle, Luxembourg, 112 S. [pp. 79-82] (PDF 3.8 MB)
• Ries, C., A. Arendt, C. Braunert, S. Christian, A. Dohet, A. Frantz, G. Geimer, M. Hellers, J. A. Massard, X. Mestdagh, R. Proess, N. Schneider & M. Pfeiffenschneider, 2017. Environmental impact assessment and black, watch and alert list classification after the ISEIA Protocol of invertebrates in Luxembourg. Bull. Soc. Nat. luxemb. 119: 63-70. [PDF 360 KB]
• Staudt, A., 2012. Nachweiskarten der Spinnentiere Deutschlands (Arachnida: Araneae, Opiliones, Pseudoscorpiones). http://www.spiderling.de/arages/
• Toss, K., 2010. Auffällig unauffällig: Der bislang unbestimmte Weberknecht der Gattung Leiobunum ist im westlichen Ruhrgebiet weit verbreitet. Elektronische Aufsätze der Biologischen Station Westliches Ruhrgebiet 19: 1-5.
• Wijnhoven, H., A.L. Schönhofer & J. Martens, 2007. An unidentified harvestman Leiobunum sp. alarmingly invading Europe (Arachnida: Opiliones). Arachnol. Mitt. 34: 27-38. (https://www.natur-in-nrw.de/Download/Martens_Leiobunum_2007.pdf)

 Page content last updated on 2026-09-22. Last proofread by Caroline Grounds on 2019-12-10.

	Sheep tick	Status LU: absent
	Schofszeck	Status Eur.: established.
	n/a	RA: ISEIA: C0. Harmonia+: n/a.
	Schafzecke	Wikipedia: | Wikispecies:
	n/a	Back to the list of invertebrates

Important note

In 2015, six Dermacentor ticks were collected in SE-Luxembourg. Previously, these individuals had been identified as Dermacentor marginatus Leach, 1815. However, morphological re-investigation as well as DNA barcoding identified the specimens as Dermacentor reticulatus (Fabricius, 1794). Thus only D. reticulatus is known from Luxembourg (Weigand et al. 2020).

Brief description

Dermacentor marginatus Leach, 1815 is a species of tick of the family Ixodidae, which is a vector of several zoonotic diseases, which is why this tick is considered to pose particular eco-epidemiological and public health risks for humans (Wikipedia contributors 2019).

In Central Europe the sheep tick is the most common species of the genus. It lives here only in heat islands and on sunny slopes or dry grasslands. Mammals, including humans, are preferred as hosts. The animals of the genus transmit tularemia (Francisella tularensis), Rocky Mountain spotted fever (Rickettsia richettsii), Q-fever (Rickettsia burneti), bovine anaplasmosis, puppy-babesiosis (Babesia canis) (Source: http://www.ijon.de/zecken/system.html#zecke).

It is one of the species that could be favoured by global warming, which would allow it to move northwards, but also upwards (Wikipedia contributors 2019).

Status and distribution in Luxembourg

The tick Dermacentor marginatus Leach, 1815 is absent from Luxembourg.

Risk assessment

ISEIA protocol

Following the morphological re-investigation as well as DNA barcoding that identified all the specimens as Dermacentor reticulatus (Fabricius, 1794) (Weigand et al. 2020), Dermacentor marginatus is considered absent from Luxembourg and was reassessed on 29 October 2020 to C0 (2+1+2+1). Initial assessment: C1 (2+1+2+1) (Ries et al. 2017: 68).

Harmonia+ protocol

Not assessed yet.

Worldwide distribution

Bibliography

• Direction de la Santé, 2016. Attention aux tiques! Comment se protéger? Dépliant. Luxembourg. URL: https://sante.public.lu/fr/prevention/tiques/
• GBIF, 2020. Dermacentor marginatus in GBIF Secretariat (2019). GBIF Backbone Taxonomy. Checklist dataset https://doi.org/10.15468/39omei [accessed 2020-03-05]
• Ries, C., A. Arendt, C. Braunert, S. Christian, A. Dohet, A. Frantz, G. Geimer, M. Hellers, J. A. Massard, X. Mestdagh, R. Proess, N. Schneider & M. Pfeiffenschneider, 2017. Environmental impact assessment and black, watch and alert list classification after the ISEIA Protocol of invertebrates in Luxembourg. Bull. Soc. Nat. luxemb. 119: 63-70. [PDF 360 KB]
• Weigand, A., J. Teixeira & S. Christian, 2020. First record of Hyalomma marginatum sensu stricto C.L. Koch, 1844 and distribution of Dermacentor reticulatus (Fabricius, 1794) (Acari, Ixodidae) in Luxembourg. Bull. Soc. nat. luxemb. 122 : 253-263.
• Wikipedia contributors, 2019. Dermacentor marginatus. Wikipédia, l’encyclopédie libre. URL: https://fr.wikipedia.org/wiki/Dermacentor_marginatus [accessed 2020-03-05]

 Page content last updated on 2022-04-27. Last proofread by Caroline Grounds on 2019-12-10.

	Red swamp crayfish, Louisiana crayfish	Status LU: isolated, first record: 2021
	Roude Suppekriibs	Status Eur.: established. IAS of EU concern (2016).
	Écrevisse de Louisiane	RA: ISEIA: A1, Black List.
	Roter Amerikanischer Sumpfkrebs	Wikipedia: | Wikispecies: | CABI
	Rode rivierkreeft	Back to the list of invertebrates

Brief description

Procambarus clarkii (Girard, 1852) is a species of cambarid freshwater crayfish, native to northern Mexico, and southern and southeastern United States, but also introduced elsewhere, where it is often an invasive pest. P. clarkii is typically dark red, with long claws and head, small or no spines on the sides of its carapace just below the head, and rows of bright red bumps on the front and side of the first leg (Wikipedia contributors 2020).

The red swamp crayfish is most commonly found in warm fresh water, such as slowly flowing rivers, marshes, reservoirs, irrigation systems and rice paddies. It is considered to be the most ecologically plastic species in the order Decapoda, and is able to grow quickly even in only seasonally present water, being able to tolerate dry spells of up to four months. The red swamp crayfish grows quickly, and is capable of reaching weights in excess of 50 g, and sizes of 5.5–12 cm long. It is also able to tolerate slightly saline water, which is unusual for a crayfish. Additionally, P. clarkii are physiologically capable of tolerating relatively low dissolved oxygen concentrations. The average lifetime of Procambarus clarkii is five years (Wikipedia contributors 2020).

The burrowing activities of the red swamp crayfish can lead to damage to water courses and to crops, particularly rice, and its feeding can disrupt native ecosystems. It may out-compete the native crayfish species, and is a vector for the crayfish plague fungus Aphanomyces astaci, for crayfish virus vibriosis, and a number of worms parasitic on vertebrates. Their burrowing activities may also be a threat to civil infrastructure such as storm ponds and levees (Wikipedia contributors 2020).

Status and distribution in Luxembourg

The Louisiana crayfish was sighted in Luxembourg for the first time on 21 September 2021 in Lake Echternach. This discovery was made as part of the LUXIAS monitoring programme (a specific monitoring programme targeting invasive alien species) carried out by LIST (Luxembourg Institute of Science and Technology). In 2022, the ANF ran a trapping campaign using traps baited with fish pellets. Using 12 traps, a total of 267 Louisiana crayfish were caught between 26 August 2022 and 10 November 2022, including numerous egg-bearing females, females carrying larvae and juveniles. Currently (August 2026), Lake Echternach remains the only known location of the Louisiana crayfish in Luxembourg. An action plan relating to the species was published in 2024.

Risk assessment

ISEIA protocol

A1 (3+3+3+3) = Alert List (Ries et al. 2017: 68).

Harmonia+ protocol

Not assessed yet.

Worldwide distribution

Bibliography

• CABI, 2019. Procambarus clarkii. In: Invasive Species Compendium. Wallingford, UK: CAB International. URL: www.cabi.org/isc [accessed 2020-03-13]
• MNHNL, iNaturalist & GBIF, 2020. Procambarus clarkii in MNHNL-mdata, online portal combining species observation from Recorder-Lux, iNaturalist and GBIF. National Museum of Natural History, Luxembourg. URL: https://mdata.mnhn.lu [accessed 2026-08-13]
• Ries, C., A. Arendt, C. Braunert, S. Christian, A. Dohet, A. Frantz, G. Geimer, M. Hellers, J. A. Massard, X. Mestdagh, R. Proess, N. Schneider & M. Pfeiffenschneider, 2017. Environmental impact assessment and black, watch and alert list classification after the ISEIA Protocol of invertebrates in Luxembourg. Bull. Soc. Nat. luxemb. 119: 63-70. [PDF 360 KB]
• Wikipedia contributors, 2020. Procambarus clarkii, Wikipedia, The Free Encyclopedia, 3 February 2020, 18:43 UTC, <https://en.wikipedia.org/w/index.php?title=Procambarus_clarkii&oldid=939000553> [accessed 2020-03-13]

 Page content last updated on 2026-09-22.

	n/a	Status LU: established. 1st record: 1991.
	Tiger-Floukriibs	Status Eur.: established.
	n/a	RA: ISEIA: C2. Harmonia+: n/a.
	Gefleckter Flussflohkrebs	Wikipedia: n/a (2020) | Wikispecies: n/a (2020)
	Tijgervlokreeft	Back to the list of invertebrates

Brief description

Gammarus tigrinus Sexton, 1939 has eliminated some native species in parts of the river Rhine and the Baltic Sea; it is frequently a superior predator in comparison to indigenous species.

See the copyrighted picture at cabi.org

Status and distribution in Luxembourg

Gammarus tigrinus Sexton, 1939 was first documented on 22 May 1991 in the Moselle river across from Bech-Kleinmacher, municipality of Schengen (Massard & Geimer 1992). Dhur (1993) showed that Gammarus tigrinus was present in the Moselle all the way from Schengen to Wasserbillig.

There is no distribution map available because no data has been entered into the Recorder-Lux database so far (MNHNL, iNaturalist & GBIF 2019).

Risk assessment

ISEIA protocol

C2 (3+1+3+1) (Ries et al. 2017: 68).

Harmonia+ protocol

Not assessed yet.

Worldwide distribution

Bibliography

• CABI, 2019. Gammarus tigrinus. In: Invasive Species Compendium. Wallingford, UK: CAB International. URL: www.cabi.org/isc [accessed 2020-03-13]
• Dhur, G., 1993. Étude des espèces d’invertébrés immigrées ou introduites dans la Moselle luxembourgeoise et dans les écosystèmes aquatiques qui en dépendent. Historique et répartition actuelle. Centre univ. Luxemb., Dép. Form. pédag., mém. sci., 213 pp.
• Dhur, G. & J.A. Massard, 1995. Etude historique et faunistique des Invertébrés immigrés ou introduits dans la Moselle luxembourgeoise et ses affluents. Bull. Soc. Nat. luxemb. 96: 127-156. [PDF 1896 KB]
• Massard, J.A. & G. Geimer, 1992. Découverte de Gammarus tigrinus Sexton, 1939 dans la Moselle frontalière entre le Luxembourg et l’Allemagne (Crustacea: Amphipoda). Bull. Soc. Nat. luxemb. 93: 195-198. [PDF 173 KB]
• Meisch, C. & J.A. Massard, 2015. Les recherches sur les crustacés (Crustacea) du Luxembourg : aperçu historique. Bull. Soc. Nat. luxemb. 116: 381-390. [PDF 1,22 MB]
• MNHNL, iNaturalist & GBIF, 2019. MNHNL-mdata, online portal combining species observation from Recorder-Lux, iNaturalist and GBIF. National Museum of Natural History, Luxembourg. URL: https://mdata.mnhn.lu [Accessed 2019-10-24]
• Ries, C., A. Arendt, C. Braunert, S. Christian, A. Dohet, A. Frantz, G. Geimer, M. Hellers, J. A. Massard, X. Mestdagh, R. Proess, N. Schneider & M. Pfeiffenschneider, 2017. Environmental impact assessment and black, watch and alert list classification after the ISEIA Protocol of invertebrates in Luxembourg. Bull. Soc. Nat. luxemb. 119: 63-70. [PDF 360 KB]

 Page content last updated on 2026-09-22. Last proofread by Caroline Grounds on 2019-12-10.

	Killer shrimp	Status LU: present. 1st record: 2006.
	Killercrevette	Status Eur.: established.
	Crevette tueuse	RA: ISEIA: A1, Black List. Harmonia+: 0,50
	Großer Höckerflohkrebs	Wikipedia: | Wikispecies: n/a (2020)
	Pontokaspische Vlokreeft	Back to the list of invertebrates

Brief description

Dikerogammarus villosus (Sowinsky, 1894) is a freshwater amphipod originating from the Ponto-Caspian region. Its range expansion began in the late twentieth century and was associated with re-opening of the shipping canal between the Danube River and Main River (Vaate et al., 2002). Large body size, extremely voracious predatory behaviour, high fecundity and wide environmental tolerance make this amphipod a very successful invader of European waters. Invasion of D. villosus often results in significant local reduction or even extinction of native amphipods and other macroinvertebrates on which it preys (CABI 2019).

D. villosus is included on the list of the 100 most invasive exotic species of Europe (Devin & Beisel 2009).

Status and distribution in Luxembourg

Dikerogammarus villosus (Sowinsky, 1894) was first recorded in 2006: several specimen collected on 2006-05-12 in the river Moselle near Stadtbredimus were discovered in the Museums collections in July 2021 (Weigand in litt.). Another observation was made on 2018-06-20 in the river Sure near Wasserbillig / Langsur (MNHNL, iNaturalist & GBIF 2021). Accordingly, the Killer shrimp has been moved from the Alert List (Ries et al. 2017: 68) to the Black List.

Risk assessment

ISEIA protocol

Following the discovery of the Killer shrimp in July 2021 in the Museums collections (Weigand in litt.), the species was reassessed on 2021-07-29 to A1 (3+2+3+3) = Black List by C. Ries. Initial assessment: A0 (3+2+3+3) = Alert List (Ries et al. 2017: 68).

Harmonia+ protocol

Overall risk score 0,50 = (Overall Invasion score 0,82 x Overall Impact score 0,61) (evaluated by Tiago De Sousa, Manou Pfeiffenschneider and Roland Proess).

Worldwide distribution

Bibliography

• CABI, 2019. Dikerogammarus villosus. In: Invasive Species Compendium. Wallingford, UK: CAB International. URL: www.cabi.org/isc [accessed 2020-03-13]
• Devin, S. & J.-N. Beisel, 2009. Dikerogammarus villosus (Sowinsky), killer shrimp (Gammaridae, Crustacea). In: Handbook of alien species in Europe. Springer, 309.
• MNHNL, iNaturalist & GBIF, 2021. Dikerogammarus villosus in MNHNL-mdata, online portal combining species observation from Recorder-Lux, iNaturalist and GBIF. National Museum of Natural History, Luxembourg. URL: https://mdata.mnhn.lu [accessed 2020-03-13]
• Ries, C., A. Arendt, C. Braunert, S. Christian, A. Dohet, A. Frantz, G. Geimer, M. Hellers, J. A. Massard, X. Mestdagh, R. Proess, N. Schneider & M. Pfeiffenschneider, 2017. Environmental impact assessment and black, watch and alert list classification after the ISEIA Protocol of invertebrates in Luxembourg. Bull. Soc. Nat. luxemb. 119: 63-70. [PDF 360 KB]

 Page content last updated on 2026-09-21. Last proofread by Caroline Grounds on 2019-12-10.

	New Zealand mud snail	Status LU: established. 1st record: 1996.
	Neiséilännesch Zwergdeckelschleek	Status Eur.: established.
	Hydrobie des antipodes	RA: ISEIA: A3, Black List. Harmonia+: n/a.
	Neuseeländische Zwergdeckelschnecke	Wikipedia: | Wikispecies: n/a (2020) | CABI
	Jenkins’ waterhoren	Back to the list of invertebrates

Brief description

Potamopyrgus antipodarum (Gray, 1843) is an aquatic snail native to New Zealand. It has been introduced to Europe, North America, Australia, Iraq, Turkey and Japan. In several ecosystems it is considered invasive because it becomes highly abundant, impacting the structure and function of the invaded ecosystems. Females are parthenogenetic, meaning they can reproduce without males, so a population can be founded by a single female. Most the non-native populations are female. There can be up to six generations per year, with an average number of 230 offspring per adult per year. P. antipodarum can also tolerate desiccation for several days, which allows for rapid spread (such as by birds and fishing tools) throughout different aquatic ecosystems. In several countries, including Spain, USA and Australia, it is considered as an invasive species (CABI 2019).

Status and distribution in Luxembourg

Potamopyrgus antipodarum (Gray, 1843) was first documented by Gerhard Weitmann and Klaus Groh on 17 June 1996 in the Moselle river in the municipality of Remich (MNHNL 2000-).

Currently, 52 records of the New Zealand mud snail are accessible through the MNHNL-mdata portal (MNHNL, iNaturalist & GBIF 2019).

Risk assessment

ISEIA protocol

A3 (3+2+3+3) = Black List (Ries et al. 2017: 68).

Harmonia+ protocol

Not assessed yet.

Worldwide distribution

Bibliography

• CABI, 2019. Potamopyrgus antipodarum (Gray, 1843). In: Invasive Species Compendium. Wallingford, UK: CAB International. URL: www.cabi.org/isc [accessed 2020-04-21]
• MNHNL, 2000-. Potamopyrgus antipodarum (Gray, 1843) in Recorder-Lux, database on the natural heritage of the Grand Duchy of Luxembourg. Musée national d’histoire naturelle, Luxembourg. URL: https://mdata.mnhn.lu [Accessed 2019-10-24]
• MNHNL, iNaturalist & GBIF, 2019. Potamopyrgus antipodarum (Gray, 1843) in MNHNL-mdata, online portal combining species observation from Recorder-Lux, iNaturalist and GBIF. National Museum of Natural History, Luxembourg. URL: https://mdata.mnhn.lu [Accessed 2019-10-24]
• Ries, C., A. Arendt, C. Braunert, S. Christian, A. Dohet, A. Frantz, G. Geimer, M. Hellers, J. A. Massard, X. Mestdagh, R. Proess, N. Schneider & M. Pfeiffenschneider, 2017. Environmental impact assessment and black, watch and alert list classification after the ISEIA Protocol of invertebrates in Luxembourg. Bull. Soc. Nat. luxemb. 119: 63-70. [PDF 360 KB]

 Page content last updated on 2026-09-22.

	Chinese pond mussel	Status LU: absent.
	Chinesesch Weiermuschel	Status Eur.: established.
	Anodonte chinois	RA: ISEIA: C0. Harmonia+: n/a.
	Chinesische Teichmuschel	Wikipedia: | Wikispecies: n/a (2020) | CABI
	n/a	Back to the list of invertebrates

Brief description

Sinanodonta woodiana (Lea, 1834) is a species of freshwater mussel, an aquatic bivalve mollusk in the family Unionidae, the river mussels. The Chinese pond mussel can reach sizes of up to 30 cm and an age of 12–14 years. Yet, they can reproduce in their first year while only 3–4 cm in size. This large freshwater mussel is a habitat generalist with high silt tolerance. It is established worldwide despite having, like all unionid mussels, an obligatory parasitic stage (glochidium), which must encyst on host fish. The species is a broad host generalist, which can complete its development on all fish species tested, both coinvasive and native. The presence of S. woodiana can seriously influence indigenous unionid populations. Sinanodonta woodiana’s great success is attributed to importation and commercialization of Asian carp, its native host. S. woodiana was introduced in Tuscany both inadvertently, and for artificial pearl production. The species is also sold in garden centers as biofiltration for artificial ponds (CABI 2019).

Status and distribution in Luxembourg

Sinanodonta woodiana (Lea, 1834) has not yet been observed in Luxembourg (MNHNL, iNaturalist & GBIF 2020).

A flyer about invasive mussels has been published by natur&ëmwelt.

Risk assessment

ISEIA protocol

C0 (2+1+2+1) (Ries et al. 2017: 68).

Harmonia+ protocol

Not assessed yet.

Worldwide distribution

Bibliography

• CABI, 2019. Sinanodonta woodiana (Lea, 1834). In: Invasive Species Compendium. Wallingford, UK: CAB International. URL: www.cabi.org/isc [accessed 2020-04-21]
• MNHNL, iNaturalist & GBIF, 2020. Sinanodonta woodiana (Lea, 1834) in MNHNL-mdata, online portal combining species observation from Recorder-Lux, iNaturalist and GBIF. National Museum of Natural History, Luxembourg. URL: https://mdata.mnhn.lu [Accessed 2020-04-21]
• Ries, C., A. Arendt, C. Braunert, S. Christian, A. Dohet, A. Frantz, G. Geimer, M. Hellers, J. A. Massard, X. Mestdagh, R. Proess, N. Schneider & M. Pfeiffenschneider, 2017. Environmental impact assessment and black, watch and alert list classification after the ISEIA Protocol of invertebrates in Luxembourg. Bull. Soc. Nat. luxemb. 119: 63-70. [PDF 360 KB]

 Page content last updated on 2026-09-22.

	n/a	Status LU: established. 1st record: 1996.
	Asiatesch Kuerfmuschel	Status Eur.: established.
	Corbicule asiatique	RA: ISEIA: A2, Black List. Harmonia+: n/a.
	Feingerippte Körbchenmuschel	Wikipedia: | Wikispecies: n/a (2020) | CABI
	Toegeknepen korfmossel	Back to the list of invertebrates

Brief description

Corbicula fluminalis (O.F. Müller, 1774) is a species of freshwater clam, an aquatic bivalve mollusk in the family Cyrenidae. This species is distinct from, but often confused with, the rather similar species Corbicula fluminea. Even though both species are native to Asia, they are both present as introduced species in the United States and Europe, and they are both commonly known as “Asian clams” (Wikipedia contributors 2019).

The original distribution area of Corbicula fluminalis includes the Near East (the type material came from the Euphrates), Central Asia (Uzbekistan) and the Caucasus (Azerbaijan) and North Africa. The animals prefer to live on sandy and muddy river bottoms. Corbicula fluminalis is found today in almost all major Central European rivers, often sympatric with Corbicula fluminea (Wikipedia Editor 2019).

Status and distribution in Luxembourg

In Luxembourg, Corbicula fluminalis (O.F. Müller, 1774) was first found by Klaus Groh on 17 June 1996 in the Moselle river in the municipality of Remich (MNHNL 2000-, Bachmann & Usseglio-Polatera 1999).

An identification sheet of the species has been published by the MECDD in French and German. A flyer about invasive mussels has been published by natur&ëmwelt.

Risk assessment

ISEIA protocol

A2 (3+3+3+3) = Black List (Ries et al. 2017: 68).

Harmonia+ protocol

Not assessed yet.

Worldwide distribution

Bibliography

• Bachmann V. & P. Usseglio-Polatera, 1999. Contribution of the macrobenthic compartment to the oxygen budget of a large regulated river: the Mosel. Hydrobiologia. 410 (17), 39-46.
• CABI, 2019. Corbicula fluminalis (O.F. Müller, 1774). In: Invasive Species Compendium. Wallingford, UK: CAB International. URL: www.cabi.org/isc [accessed 2020-04-21]
• MNHNL, 2000-. Corbicula fluminalis (O.F. Müller, 1774) in Recorder-Lux, database on the natural heritage of the Grand Duchy of Luxembourg. Musée national d’histoire naturelle, Luxembourg. URL: https://mdata.mnhn.lu [Accessed 2019-10-24]
• MNHNL, iNaturalist & GBIF, 2019. Corbicula fluminalis (O.F. Müller, 1774) in MNHNL-mdata, online portal combining species observation from Recorder-Lux, iNaturalist and GBIF. National Museum of Natural History, Luxembourg. URL: https://mdata.mnhn.lu [Accessed 2019-10-24]
• Ries, C., A. Arendt, C. Braunert, S. Christian, A. Dohet, A. Frantz, G. Geimer, M. Hellers, J. A. Massard, X. Mestdagh, R. Proess, N. Schneider & M. Pfeiffenschneider, 2017. Environmental impact assessment and black, watch and alert list classification after the ISEIA Protocol of invertebrates in Luxembourg. Bull. Soc. Nat. luxemb. 119: 63-70. [PDF 360 KB]
• Wikipedia Bearbeiter, 2019. Feingerippte Körbchenmuschel. In: Wikipedia, Die freie Enzyklopädie. Bearbeitungsstand: 20. Dezember 2019, 15:19 UTC. URL: https://de.wikipedia.org/w/index.php?title=Feingerippte_K%C3%B6rbchenmuschel&oldid=195082277 [accessed 2020-04-21]
• Wikipedia contributors, 2019. Corbicula fluminalis, Wikipedia, The Free Encyclopedia, 10 April 2019, 21:39 UTC, <https://en.wikipedia.org/w/index.php?title=Corbicula_fluminalis&oldid=891900774> [accessed 2020-04-21]

 Page content last updated on 2024-09-09.