Marbled crayfish in Korea

An interesting paper by Park and Jeon (2023) mentioned that South Korea imports about 78,000 crayfish as pets a year from 2018 to 2022. They describe 34 species imported.

 

I was surprised to see that marbled crayfish are not one of those species listed as being in the Korean pet trade at all. Usually they would be not only widely available, but one of the highest risk species.

 

But this YouTube video strongly suggests marbled crayfish are available in Korea.

 

Reference

Park Y, Jeon Y. 2023. A study on the import status of pet freshwater crayfish and potential invasive alien species crayfish in Korea. Korean Journal of Ecology and Environment 56(3): 242-249. https://doi.org/10.11614/KSL.2023.56.3.242
 

Scheers 2023

Scheers K. 2023. The illegal trade of marbled crayfish in Belgium: an ongoing risk for further spread. Presentation given to CrayfIT 2023 conference. https://crayfit.eu/wp-content/uploads/2023/09/Crayfit-Book-of-Abstracts.pdf

Abstract

The marbled crayfish (Procambarus virginalis) is a well-known invasive species. This parthenogenetic species originated from the aquarium trade and has been introduced in many European countries. Because of its highly invasive character this species was included on the list of Invasive Species of Union Concern in 2016 because of its potential as a highly invasive species. This resulted in a total ban of the trade, breeding and keeping of marbled crayfish in the European Union. To ascertain if marbled crayfish are still being traded in Belgium, the major online classified platforms were regularly monitored from 26-04-2022 to 01-08-2023 for the sale of the banned marbled crayfish. The results of this survey show that the marbled crayfish is still commonly being traded online and indicate the high risk of further spread.

 

Keywords: marbled crayfish • Procambarus virginalis • trade • legislation • enforcement

Xiao and Faulkes 2023

Xiao J, Faulkes Z. 2023. Online advertisements for crayfish decrease after a provincial ban. ARPHA Preprints. https://preprints.arphahub.com/article/107487, https://doi.org/10.3897/arphapreprints.e107487 (DOI link not working yet)

Abstract

The parthenogenetic marbled crayfish, Procambarus virginalis, is an unwanted species introduced in many countries. There are no established populations in North America to date. Several jurisdictions in the United States and Canada have specifically banned ownership of marbled crayfish, but it is unclear if such bans effectively reduce ownership. The Canadian province of Saskatchewan prohibited marbled crayfish in 2020. We tested whether the introduction of this law affected behaviour by comparing online advertisements for crayfish in Saskatchewan and other Canadian provinces over two years before and after the ban. The number of online advertisements and sellers in Saskatchewan for all crayfish – not just marbled crayfish – was significantly smaller after the ban. No other province showed this pattern. This suggests banning marbled crayfish reduced the online availability of crayfish and may be an example of a successful policy to reduce availability of aquarium pets.

Keywords: Marmorkrebs • crayfish • pet trade • aquarium • policy

Note: This is an unreviewed preprint.

 

Bláha and colleagues 2022

Bláha M, Weiperth A, Patoka J, Szajbert B, Balogh ER, Staszny Á, Ferincz Á, Lente V, Maciaszek R, Kouba A. 2022. The pet trade as a source of non-native decapods: the case of crayfish and shrimps in a thermal waterbody in Hungary. Environmental Monitoring and Assessment 194(10): 795. https://doi-org.libaccess.lib.mcmaster.ca/10.1007/s10661-022-10361-9

Abstract

Ornamental aquaculture and the related pet industry are known to be important sources of non-native species worldwide. In the temperate zone, thermal waterbodies are attractive places for irresponsible owners to release unwanted freshwater pets including decapod crustaceans. Several non-native ornamental species have been reported in the thermal locality of Miskolctapolca (a suburb of Miskolc, Hungary). So we surveyed this site in March 2019–November 2021 to update local occurrence records and detect potentially newly released species. A well-established population of Neocaridina denticulata and the occurrence of Caridina cf. babaulti had previously been noted. However, for the first time at this site, we found the shrimps Atyopsis moluccensis, Caridina gracilirostris and C. multidentata, as well as the crayfish Procambarus virginalis, P. clarkii, Cherax quadricarinatus, C. boesemani and C. snowden, and several formally undescribed Cherax species originating from New Guinea. Furthermore, in most species, gravid females carrying eggs were also noticed. Three shrimps, A. moluccensis, C. gracilirostris and C. multidentata, were recorded for the first time in European wild. Further monitoring of this locality and better education of the general public regarding the risks associated with the release of non-native species are strongly recommended.

 

Keywords: Ornamental species • invasive species • Decapoda • Europe • thermal water

Anastácio and colleagues, 2019

Anastácio PM, Ribeiro F, Capinha C, Banha F, Gama M, Filipe AF, Rebelo R, Sousa R. 2019. Non-native freshwater fauna in Portugal: A review. Science of The Total Environment 650: 1923-1934. https://doi.org/10.1016/j.scitotenv.2018.09.251

Abstract

We present the most updated list of non-native freshwater fauna established in Portugal, including the Azores and Madeira archipelagos. This list includes 67 species at national level but corresponds to 84 species records, of which 53 are in the mainland, 23 in the Azores and 8 in Madeira archipelagos. We also discuss the progression of the cumulative number of introductions since 1800 and identify the most probable vectors of introduction, main taxonomic groups and their regions of origin. Furthermore, we review the existing knowledge about ecological and economic impacts, invasion risk and potential distribution of invaders, under present and future climatic conditions, and the applied management actions, including the production of legislation. Along the 20th century the number of successful introductions increased at an approximate rate of two new species per decade until the beginning of 1970s. Since then, this rate increased to about 14 new species per decade. These introductions were mainly a result of fisheries, as contaminants or for ornamental purposes. Fish and mollusks are the taxonomic groups with more established species, representing more than half of the total. Most species (>70%) are native from other regions of Europe and North America. Studies about ecological or socioeconomic impacts are more common for fish, crustaceans and mollusks. Impacts for most amphibians, reptiles and mammals are not thoroughly studied. A few studies on the impacts and management actions of health-threatening mosquitoes are also available. The potential distribution in the Portuguese territory was modelled for 26 species. Only a minority of these models provides projections of distributions under scenarios of future climate change. A comparison of the Portuguese and EU legislation shows large discrepancies in the invasive species lists. Using the EU list and a ranking procedure for the national context, we identify freshwater species of high national concern for which actions are urgently needed.

Keywords: invasions • exotic species • Iberian Peninsula • risk assessment • inland waters • aquatic systems

Crayfish crimes

Prosecutions for anything to do with the aquarium trade is rare, but last week, news reported Justin Doyle Pierce, an American was prosecuted for selling crayfish as pets, in violation of the Lacey Act)

Pierce sold over $19,000 worth of crayfish illegally, and for this, he got a $500 fine, 20 hours of community service, and a year on probation. By my quick scan of the act, he could have received jail time and thousands of dollars in fines.

Is this sort of enforcement acting as a deterrent? It’s not clear. When someone can make that much money, the fine is little more than a clap on the wrist. The real penalty may not be the fine or the service, but the criminal record. Pierce wrote:

(T)his will result in my disqualification of future employment in areas related to wildlife and conservation.

External links

Feds pinch Camden County man for illegal crayfish sales
Overview of the Lacey Act (16 U.S.C. SS 3371-3378)
Lacey Act cases

The Lausanne Resolution turns 30

Today marks the 30^th anniversary of the Lausanne Resolution, when the world’s leading crayfish experts of the day said to governments, “Stop importing crayfish.”

All of the points listed as reasons to support the resolution are still true.

The resolution is currently up on the International Association for Astacology website as a scanned PDF). This was published in an issue of the journal Freshwater Crayfish (volume 7, page XI), although no PDF of that issue is online yet. I am reproducing it here so that there is a version on the web that is more readily available, discoverable by search engines, and shared, either on social media or by good ol’ cutting and pasting.

RESOLUTION

7^th International Symposium of Astacology - Lausanne, Switzerland,

August 5, 1987

---

The Astacologists of the International Association of Astacology meeting in its seventh International symposium in Lausanne, Switzerland, August 3-5, 1987, have noted:

• the damaging effects to live crayfish markets following the drastic decline in Turkish crayfish production,
• the marketing of new living crayfish species from many different places,
• the total absence of guarantees that such crayfish do not carry communicable parasites and diseases.
• the appearance of epidemics in European crayfish of aphanomycosis (the crayfish plague parasite), especially where it has not previously existed,
• the accrued risks of transmission of parasites and diseases, especially aphanomycosis, from other crayfish populations to native crayfish,
• the grave menace to native crayfish populations from introduction of undesirable exotic crayfish, and
• the potential for exposing fish to diseases and parasites born by crayfish.

Therefore, in view of the need for conservation of indigenous species and populations, we recommend that Governments find the means to stop the importation of living crayfish into their countries for any purpose (food, fish bait, pets, etc.), except for governmentally approved research, restockings or introductions.

Further, those Governments should be responsible for assuring that such living crayfish are parasite and disease free. Finally, Governments should encourage the restoration of native crayfish stocks wherever possible.

We encourage the immediate international adoption of this resolution.

---

Reference

International Association of Astacology. 1988. Lausanne Resolution. Freshwater Crayfish 7: XI. http://www.freshwatercrayfish.org/docs/Lausanne_Resolution_1987.pdf

Vodovsky and colleagues, 2017

Vodovsky N, Patoka J, Kouba A. 2017. Ecosystem of Caspian Sea threatened by pet-traded non-indigenous crayfish. Biological Invasions 19(7): 2207–2217. https://doi.org/10.1007/s10530-017-1433-1

Abstract

Freshwater ecosystems are particularly vulnerable to biological invasions; the aquatic animal pet trade has been recognized as a significant pathway of introductions. Crayfish are considered a model group of traded organisms with a series of highly successful species already established in the wild, having the potential to negatively influence both indigenous crayfish species (ICS) as well as alter occupied ecosystems. Eastern Europe includes the entire native ranges of indigenous Astacus leptodactylus sensu lato and A. pachypus. This region has been largely overlooked and considered relatively safe from the adverse impacts of non-indigenous crayfish species (NICS). In this study, we evaluated the crayfish pet trade in the Lower Volga Region with special emphasis on Astrakhan, the biggest city of Russian Federation in the region located just in the delta of Volga River, thus being a potential gateway of introductions to the Caspian Sea and adjacent freshwaters. The local pet trade involves 12 NICS. Considering their origin, availability, probability of establishment, invasiveness and further aspects, Procambarus fallax f. virginalis, P. clarkii and Cherax destructor are considered potentially the most problematic, including transmission of diseases like crayfish plague caused by Aphanomyces astaci or white spot syndrome virus. Taking this information as a whole, the availability of NICS with a high probability of overlapping the entire range of European ICS means that attention is warranted. Further research is needed to corroborate the abilities of NICS and their associated diseases to withstand specific conditions of the Caspian Sea as well as the adjacent Black and Azov Seas, all possessing different degrees of elevated salinity.

Keywords: aquarium • invasiveness • ornamental animal • Pet trade • Russian Federation • salinity

Chucholl and Wendler, 2017

Chucholl C, Wendler F. 2017. Positive selection of beautiful invaders: long-term persistence and bio-invasion risk of freshwater crayfish in the pet trade. Biological Invasions 19(1): 197-208. http://dx.doi.org/10.1007/s10530-016-1272-5

Abstract

After interest in keeping crayfish (Crustacea, Decapoda, Astacida) in home aquaria peaked in the mid-2000s, the aquarium trade has become a novel introduction pathway for non-native crayfish species in Germany. Here, we provide an update on the ornamental crayfish trade approximately one decade after the ‘crayfish hype’ to explore the long-term implications in terms of bio-invasion risk. Specifically, species’ availability in e-commerce and potential invasiveness were assessed and compared to previous studies. Morphological and ecological traits of the offered species were compiled and related to their long-term availability (covering 2005–2015). In July 2015, a total of 31 online shops offered 28 crayfish species, which represents a decline of 24% in species diversity compared to the late 2000s. The estimated rate of import of new species has considerably flattened and approaches pre-hype values (<1 species year⁻¹). However, the risk associated with the offered species, as assessed by a risk screening tool, has not decreased compared to the late 2000s. Long-term availability in the trade was primarily determined by bright coloration, the ability to reproduce under warm aquarium conditions, and a preference for lentic habitats. Species featuring such traits are likely to persist in the aquarium trade and include four high-risk species, most notably invasive and crayfish plague-carrying red swamp crayfish (Procambarus clarkii) and Marmorkrebs (Procambarus fallax f. virginalis). Persistent propagule pressure from aquaria has substantially contributed to the establishment of both species in Germany, stressing the need for more effective pathway management.

Keywords: aquarium trade • Crustacea • risk assessment • pre-introduction selection

Listing a species as “injurious”

The Center for Invasive Species Prevention was about to ask the US Fish and Wildlife Service to add Louisiana red swamp crayfish (Procambarus clarkii) to a list of “injurious” species.

In the petition, the CISP says the red swamp crawfish does not provide any essential economic or other benefits that outweigh their current and potential harm to the United States. ...

If the proposed changes are adopted then it could limit or prohibit the sale and export of crawfish across state lines.

But the day after I read the news article announcing that, the Center backed off. Judging from the news story and memo, it looked like the petition caused a bit of a freak out among people who sell the beast for food.

I think it’s a very interesting window into regulation. Biologically, there is no question that P. clarkii is a problematic invasive. It’s caused problems worldwide, from being farmed for aquaculture and is one of the most widely distributed crayfish in the pet trade (one of the “big six” worldwide). I think you would be hard pressed to find any biologist specializing in crayfish or invasive species that wouldn’t consider P. clarkii an extremely successful and problematic invasive species.

But there is so much established trade already within the U.S. that it is completely unsurprising that there would be pressure to not change anything.

The food industry is large and powerful. So is the pet industry, the other main mover of crayfish today. And the trade is largely unregulated, particularly for invertebrates. Although crayfish are not particularly popular in the US as pets right now, the European experience in the 1990s shows that there could easily be a “boom” in interest.

External links

Are crawfish an invasive species? Warning: contains annoying auto-play video
Statement of the Center for Invasive Species prevention on withdrawing its proposal to the U.S. Fish and Wildlife Service to add the red swamp crayfish to the Lacey act for further analysis

Picture by Michael Bok on Flickr.

Kotovska and colleagues, 2016

Kotovska G, Khrystenko D, Patoka J, Kouba A. 2016. East European crayfish stocks at risk: arrival of non-indigenous crayfish species. Knowledge and Management of Aquatic Ecosystems 417: 37. http://dx.doi.org/10.1051/kmae/2016024

Abstract

An increasing number of non-indigenous crayfish species (NICS) of apparently pet trade origin have become established particularly in Europe. Especially alarming are recent confirmation of two distantly separated marbled crayfish Procambarus fallax f. virginalis populations in Ukraine and indications of more North American cambarids present in the local pet market. The present study aimed to investigate crayfish species availability within the Ukrainian pet trade together with the climate match and risk they represent to the freshwater ecosystems generally and indigenous crayfish species in particular. Altogether, 15 NICS belonging to all three crayfish families were detected. Considering their origin, availability, probability of establishment, invasiveness and further aspects, marbled crayfish and red swamp crayfish Procambarus clarkii appear to be potentially the most troubling. Available information obtained from the pet trade in ornamental crayfish as a whole demonstrates that the broad availability of NICS most probably overlaps the vast majority of European indigenous crayfish species distribution, including the endemic thick-clawed crayfish Astacus pachypus, which occupies only a limited area that is situated critically close to established marbled crayfish populations. Negative effects of NICS on freshwater ecosystems as a whole can be also expected.

Key words: Ukraine • pet trade • ornamental animal • invasiveness • aquarium

Owning Marmorkrebs in Tennessee might just be illegal now

I ran across a notice that Marmorkrebs have been added to Tennessee’s list of “Class V wildlife.” (Update, 25 January 2016: the link is already busted.) This is the entirety of the text I have right now (my emphasis and sics)

11649

Author TN Wildlife Resources Agency

Bill Type REG

Bill Location TN WILDLIFE RESOURCES AGENCY

Amends Section 1160-01-18-03 of Tennessee Administrative Code to add the African clawed frog (Xenopus lacvis) (sic) and Marbled crayfish (Procaburus (sic) fallax f. virginalis) to the list of species classified as Class V Wildlife.

States Tennessee

Action RULED ADOPTED ON 7/24/15 - EFFECTIVE 10/22/15

It would not surprise me if Marmorkrebs were the subject of legislation in Tennessee, because that state is near, if not the center, of the world’s hotspot for crayfish biodiversity. Non-indigenous crayfish could cause a large number of problems for indigenous crayfish species in Tenessee.

I wanted to confirm this, but, somewhat to my surprise, my initial tooling around in Tennessee government websites yielded nothing. Even with what appears to be a fairly detailed description of the source of information, I can’t find it.

It took several tries to even find a definition of what “Class V Wildlife” in Tennessee means. Searching the Tennessee Wildlife Resource Agency home page gave me nothing. It was only until I backed up to Google that I found this definition:

Class V
--
This class includes such species that the commission, in conjunction with the commissioner of agriculture, may designate by rules and regulations as injurious to the environment. Species so designated may only be held in zoos under such conditions as to prevent the release or escape of such wildlife into the environment.

But I still can’t find a simple list of “Class V species” to figure out if Marmorkrebs are on it.

I will continue to investigate.

This is a nice example of that I made in a recent paper:

The regulations concerning crayfish trade are inconsistent across jurisdictions, hard to find, receive minimal enforcement, and are rarely enacted until after a problem occurs(.)

Chucholl, 2016

Chucholl C. 2016. Marbled crayfish gaining ground in Europe: the role of the pet trade as invasion pathway. In: T Kawai, Z Faulkes, G Scholtz, eds. Freshwater Crayfish: A Global Overview, pp. 83-114. Boca Raton: CRC Press. https://www.crcpress.com/Freshwater-Crayfish-A-Global-Overview/Kawai-Faulkes-Scholtz/9781466586390

Excerpt

In this chapter, knowledge on this novel and on-going pathway for alien crayfish species introductions will be reviewed. In line with the other chapters in this section, emphasis will be placed on the marbled crayfish (Procambarus fallax f. virginalis Martin et al. 2010). The history of the marbled crayfish is inseparably tied to the aquarium trade, which introduced this species to the scientific world and which, at the time of this writing, is still the only known ‘natural habitat’ of marbled crayfish.

Keywords: None provided.

Related posts

Kawai and colleagues (editors), 2016

Faulkes, 2015b

Faulkes Z. 2015. Marmorkrebs (Procambarus fallax f. virginalis) are the most popular crayfish in the North American pet trade. Knowledge and Management of Aquatic Ecosystems 416: 20. http://dx.doi.org/10.1051/kmae/2015016

Abstract

Introductions of non-native crayfish around the world are increasingly tied to the distribution, sale, and eventual release of pet crayfish. As part of risk assessment for the introduction of non-native crayfish in North America, I monitored the sale of crayfish on an auction website that specializes in aquatic pets and aquarium supplies for a year. Three species accounted for the majority of sales: the parthenogenetic crayfish, Marmorkrebs (Procambarus fallax f. virginalis), the Cajun dwarf crayfish (Cambarellus shufeldtii), and the orange morph of the endangered Mexican dwarf crayfish (Cambarellus patzcuarensis). Almost half of individual crayfish sold (48.5%) were Marmorkrebs, which is more than twice as many as C. shufeldtii, the second most commonly sold species. The Louisiana red swamp crayfish (Procambarus clarkii) was often offered for auction, but was bought much less often than the other three species. About 11% of P. clarkii auctions were successful, while more than 45% of auctions were successful for the other three. Four Cherax species were the only crayfish sold online whose native range was outside North America. Neither Marmorkrebs nor the orange morph of C. patzcuarensis can be collected regularly from natural habitats in North America, suggesting that most crayfish sold online in North America are obtained from existing stocks in the pet trade, rather than being collected from natural habitats.

Keywords: marbled crayfish • pet trade • Marmorkrebs • Cambarellus

Supplemental information: Faulkes Z. 2015. Crayfish pet trade in North America. figshare. http://dx.doi.org/10.6084/m9.figshare.1478015

Mrugała and colleagues, 2015

Mrugała A, Kozubíková-Balcarová E, Chucholl C, Cabanillas Resino S, Viljamaa-Dirks S, Vukić J, Petrusek A. 2015. Trade of ornamental crayfish in Europe as a possible introduction pathway for important crustacean diseases: crayfish plague and white spot syndrome. Biological Invasions 17(5): 1313-1326. http://dx.doi.org/10.1007/s10530-014-0795-x

Abstract

Rapidly growing trade of ornamental animals may represent an entry pathway for emerging pathogens; this may concern freshwater crayfish that are increasingly popular pets. Infected crayfish and contaminated water from aquaria may be released to open waters, thus endangering native crustacean fauna. We tested whether various non-European crayfish species available in the pet trade in Germany and the Czech Republic are carriers of two significant crustacean pathogens, the crayfish plague agent Aphanomyces astaci and the white spot syndrome virus (WSSV). The former infects primarily freshwater crayfish (causing substantial losses in native European species), the latter is particularly known for economic losses in shrimp aquacultures. We screened 242 individuals of 19 North American and Australasian crayfish taxa (the identity of which was validated by DNA barcoding) for these pathogens, using molecular methods recommended by the World Organisation for Animal Health. A. astaci DNA was detected in eight American and one Australian crayfish species, comprising in total 27 % of screened batches. Furthermore, viability of A. astaci was confirmed by its isolation to axenic cultures from three host taxa, including the parthenogenetic invader Marmorkrebs (Procambarus fallax f. virginalis). In contrast, WSSV was only confirmed in three individuals of Australian Cherax quadricarinatus. Despite modest prevalence of detected infections, our results demonstrate the potential of disease entry and spread through this pathway, and should be considered if any trade regulations are imposed. Our study highlights the need for screening for pathogens in the ornamental trade as one of the steps to prevent the transmission of emerging diseases to wildlife.

Keywords: aquarium trade • exotic pathogens • Aphanomyces astaci • white spot syndrome virus • Marmorkrebs • DNA barcoding

Marmorkrebs: the Early Years

Chris Lukhaup was one of the co-authors of the paper that introduced Marmorkrebs to the scientific world (Scholtz et al. 2003). He has been active in describing many new species of crustaceans, often emerging from the pet trade (for example, Lukhaup & Pekny 2006, 2008). He takes stunning pictures. He recently contacted me with this bit of history about Marmorkrebs, which I share with his permission (lightly edited):

When I contacted Jay Huner in Louisiana back in 2000 to tell him that I believe that the Marmorkrebs is a parthenogenetic species, he wrote me back and told me that this is impossible! I sent him some animals to check and he wrote me back that this was Procambarus clarkii. ;-) Also he told me that I need to look better because there have to be males and I should learn the difference between males and females.

In 2002, I had my first articles in some aquarium magazines describing the animal and warning already. I wrote an article and offered $3000 for a person bringing me a male Marmorkrebs... this was published in several magazines but nothing happened. Then I went to the USA myself to collect, and I was pretty sure that the Marmorkrebs was very close to Procambarus fallax. I send some animals to Berlin and they approved it. So this is the story of the Marmorkrebs from my side.

Thank you for providing that bit of history!

Reference

Lukhaup C, Pekny R. 2006. Cherax (Cherax) holthuisi, a new species of crayfish (Crustacea: Decapoda: Parastacidae) from the centre of the Vogelkop Peninsula in Irian Jaya (West New Guinea), Indonesia. Zoologische Mededelingen 80(1): 101-107. http://www.repository.naturalis.nl/document/41228

Lukhaup C, Pekny R. 2008. Cherax (Astaconephrops) boesemani, a new species of crayfish (Crustacea: Decapoda: Parastacidae) from the centre of the Vogelkop Peninsula in Irian Jaya (West New Guinea), Indonesia. Zoologische Mededelingen 82: 331-340. http://www.zoologischemededelingen.nl/82/nr02/a33


Scholtz G, Braband A, Tolley L, Reimann A, Mittmann B, Lukhaup C, Steuerwald F, Vogt G. 2003. Parthenogenesis in an outsider crayfish. Nature 421(6925): 806-806. http://dx.doi.org/10.1038/421806a

External links

Chris Lukhaup on Facebook
Chris Lukhaup’s pictures on Flickr

Faulkes, 2015

Faulkes Z. 2015. A bomb set to drop: parthenogenetic Marmorkrebs for sale in Ireland, a European location without non-indigenous crayfish. Management of Biological Invasions 6(1): 111-114. http://dx.doi.org/10.3391/mbi.2015.6.1.09

Abstract

Ireland is one of the few locations in Europe where non-indigenous North American crayfish species have not been introduced, and is a refuge for endangered white-clawed crayfish, Austropotamobius pallipes (Lereboullet, 1858). The parthenogenetic crayfish species Marmorkrebs, Procambarus fallax f. virginalis (Hagen, 1870), is sold in the pet trade in Ireland within the recorded range of A. pallipes. Marmorkrebs risk being introduced into Irish waters, where they could threaten A. pallipes populations, particularly as a vector for crayfish plague.

Keywords: Marmorkrebs • Procambarus fallax f. virginalis • Austropotamobius pallipes • pet trade • Ireland • non-indigenous crayfish species

Patoka and colleagues, 2014

Patoka J, Kalous L, Kopecký O. 2014. Risk assessment of the crayfish pet trade based on data from the Czech Republic. Biological Invasions 16(12): 2489-2494. http://dx.doi.org/10.1007/s10530-014-0682-5

Abstract

The pet trade in freshwater crustaceans, including crayfish, has grown rapidly in recent decades and become an important pathway for introducing new non-indigenous species into Europe. This paper provides the first overview of non-indigenous crayfish species (NICS) traded as ornamental and their potential impact in the Czech Republic, which is the second leading importer into Europe. The paper presents a full list of traded crayfish species, their market availability, and trade names or misnomers used in the country. In total, 27 crayfish species from all three families are advertised and marketed, of which Astacus astacus is the only indigenous species. Only three NICS were recognized as very common on the market. The invasiveness and risk associated with ornamental crayfish trade were assessed using the Freshwater Invertebrate Invasiveness Scoring Kit. Five NICS were classified into the high-risk category, the highest score being for Procambarus fallax f. virginalis. The invasiveness of crayfish indigenous to North America is significantly greater than that of crayfish from the rest of the world, and therefore regulation in this regard is recommended.

Keywords: Ornamental animal • Invasiveness • FI-ISK • Aquarium • Trade names

Chucholl, 2014

Chucholl C. 2014. Predicting the risk of introduction and establishment of an exotic aquarium animal in Europe: insights from one decade of Marmorkrebs (Crustacea, Astacida, Cambaridae) releases. Management of Biological Invasions 5(4): 309-318. http://dx.doi.org/10.3391/mbi.2014.5.4.01

Abstract

The presence of the North American Marmorkrebs (Procambarus fallax f. virginalis) in European inland waters is entirely driven by ongoing propagule pressure from the ornamental trade. Since 2003 at least 25 independent introduction events have been confirmed, of which some have eventually resulted in established populations. This study links a maximum-entropy model that forecasts the probability of Marmorkrebs introduction based on socio-economic predictors to an updated species distribution model based on environmental predictors in order to explore the risk of further Marmorkrebs establishment in Europe. In line with related research, the probability of Marmorkrebs release was largely affected by gross domestic product and human population density, i.e. predictors very likely related to the density of Marmorkrebs owners, whereas environmental suitability was mostly influenced by minimum temperature and the availability of lentic habitats, which was indirectly assessed by terrain slope. While considerable parts of Europe were predicted as potentially suitable for establishment, high probabilities of introduction were forecasted in much smaller geographic areas. The consensus map of the model predictions suggests that introduction and subsequent establishment of Marmorkrebs is likely to occur in much of Germany, the Benelux countries, England, Italy, and areas of high human population density throughout France and Spain, as well as parts of southernmost Scandinavia and Southeastern Europe. Monitoring trades of Marmorkrebs in these high-risk regions is recommended and implications for proactive measures are discussed, including the need for consistent trade regulations at the EU level.

Keywords: marbled crayfish • propagule pressure • risk assessment • ornamental trade • introduction pathway

The eight most popular crayfish

Those keeping crayfish as pets might be interested in Chris Lukhaup’s round-up, Freshwater Aquarium Crayfish.

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