Without abstract. Excerpt:
The awards committee... evaluated the presentations and posters by young scientists. This year, prizes were exclusively awarded for oral presentations. The winners were Przemysław Piekarczyk... and Kamil Wiśniewski, a doctoral student at Nicolaus Copernicus University in Toruń, for his talk on Clonal invasion: habitat preferences of juvenile, parthenogenetic marbled crayfish (Procambarus virginalis).
Keywords: None.
Background: Introducing invasive alien species can reduce biodiversity by interfering with native species or spreading disease and having socioeconomic consequences. Therefore, international society has set goals for preventing and suppressing the introduction and spread of invasive alien species. Nevertheless, humans intentionally introduce and release alien species into the wild, facilitating their invasion. Procambarus virginalis (marbled crayfish) is a Decapoda invertebrate sold for ornamental purposes. Ecological repercussions are anticipated because individuals have been verified to exist in the wild in South Korea. P. virginalis, believed to have originated in Europe and North America, is parthenogenetic. Therefore, there is concern that its population may quickly expand in the natural environment.
Results: This study examined the invasion risk of P. virginalis in South Korea and predicted its dispersal under future climatic circumstances. The habitat suitability for P. virginalis
in Europe, North America, and Northeast Asia was determined using an
ensemble species distribution model, and climatic niches were compared.
Furthermore, the distributions of South Korea under the SSP2-4.5 and
SSP5-8.5 scenarios are provided. The Northeast Asian region had habitat
suitability comparable to that of Europe, and there was evidence that
its climatic niche overlapped Europe (Schoener’s D = 0.29). In the
future climatic scenario, 38% of South Korea is at risk of moderate to
low invasion. The human disturbance index was the most critical variable
in the distribution.
Conclusions: We believe the hazards of
its invasion of South Korea are significant. Additionally, there is a
high possibility that they will be established in nature due to
artificial releases. Therefore, continuous monitoring and appropriate
management are needed for areas with a high risk of P. virginalis invasion.
Keywords: ensemble species distribution model • human influence index • invasive species • niche overlap • Procambarus virginalis
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.
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
World of Crayfish™ is an ambitious new website that shows the geographic distribution of crayfish species in near real-time.
Of course, I checked for whether there was a Marmorkrebs map. There is! Click to enlarge!
It’s clearly out of date in some ways. I expected to see records from Madagascar, as several localities published in peer-reviewed journals have been available for some time. On the other hand, there seem to be new records that I have not found yet, like in southern France.
Nevertheless, this seems like a much more organized effort that might eventually supplant my own map of Marmorkrebs introductions.
Ion MC, Bloomer CC, Bărăscu TI, Oficialdegui FJ, Shoobs NF, Williams BW, Scheers K, Clavero M, Grandjean F, Collas M, Baudry T, Loughman Z, Wright JJ, Ruokonen TJ, Chucholl C, Guareschi S, Koese B, Banyai ZM, Hodson J, Hurt M, Kaldre K, Lipták B, Fetzner JW, Cancellario T, Weiperth A, Birzaks Jn, Trichkova T, Todorov M, Balalaikins M, Griffin B, Petko ON, Acevedo-Alonso A, D’Elía G, Śliwińska K, Alekhnovich A, Choong H, South J, Whiterod N, Zorić K, Haase P, Soto I, Brady DJ, Haubrock PJ, Torres PJ, Şadrin D, Vlach P, Kaya C, Woo Jung S, Kim J-Y, Vermeersch XHC, Bonk M, Guiaşu R, Harlioğlu MM, Devlin J, Kurtul I, Błońska D, Boets P, Masigol H, Cabe PR, Jussila J, Vrålstad T, Beresford DV, Reid SM, Patoka J, Strand DA, Tarkan AS, Steen F, Abeel T, Harwood M, Auer S, Kelly S, Giantsis IA, Maciaszek R, Alvanou MV, Aksu Ö, Hayes DM, Kawai T, Tricarico E, Chakandinakira A, Barnett ZC, Kudor ŞG, Beda AE, Vîlcea L, Mizeranschi AE, Neagul M, Licz A, Cotoarbă AD, Petrusek A, Kouba A, Taylor CA, Pârvulescu L. 2024. World of Crayfish™: A web platform towards real-time global mapping of freshwater crayfish and their pathogens. PeerJ 12: e18229. https://doi.org/10.7717/peerj.18229
Invasive crayfish have become well-established in Flanders. Most of the species are widespread and eradication seems improbable. Yet, managers are looking for control measures to mitigate the density dependent impacts of invasive crayfish. This preliminary experiment explores predation of two benthic predatory fish burbot (Lota lota) and European catfish (Silurus glanis) on the marbled crayfish (Procambarus virginalis) and evaluates their potential for use as a future control measure.
Keywords: None provided.
Edit, 26 November 2024: YouTube video, apparently by the first author, showing some foraging behaviour of the European catfish:
Thammatorn W, Kouba A, Nováková P, Žlábek V, Koubová A. 2024. Effects of diphenhydramine on crayfish cytochrome P450 activity and antioxidant defence mechanisms: First evidence of CYP2C- and CYP3A-like activity in marbled crayfish. Ecotoxicology and Environmental Safety 285: 117035. https://doi.org/10.1016/j.ecoenv.2024.117035
Growing evidence has reported that diphenhydramine (DPH), an ionisable antihistamine, is widely present in surface waters across the world. Relative to vertebrates studied, its impact on invertebrates, particularly concerning cytochrome P450 (CYP) metabolism and oxidative stress, remains poorly understood. In this study, we aimed to investigate the effects of 2, 20, and 200 µg/L DPH on marbled crayfish (Procambarus virginalis) after 96-h exposure. Specifically, we assessed CYP activity, antioxidant enzyme responses, and acetylcholinesterase (AChE) activity in gills, muscle, and hepatopancreas. The crayfish CYP metabolised fluorogenic CYP-metabolic substrates of 7-benzyloxy-4-trifluoromethylcoumarin (BFC) and dibenzylfluorescein (DBF), which evidenced the activity of CYP2C and CYP3A isoforms, well known in mammalian detoxification metabolism. Both BFC and DBF dealkylations showed a positive correlation with each other but were negatively correlated to water and haemolymph DPH concentrations. Exposure to 200 µg/L DPH elicited an apparent inhibition trend, albeit not significant, in BFC- and DBF-transformation activities in crayfish. Other tested 7-benzyloxyresorufin and 7-pentoxyresorufin substrates were poorly metabolised, suggesting their relatively low activity or the lack of mammalian-like CYP1A and CYP2B isoforms in marbled crayfish. The significant modulation of antioxidant enzymes was demonstrated in gills and hepatopancreas. The exposure to DPH did not alter the activity of AChE. Integrated biomarker response version 2 showed the highest cumulative effect of DPH exposure on gills, implying that gill tissue is the most reliable matrix for evaluating DPH toxicity. Activities of glutathione peroxidase and glutathione-S-transferase were the most deviated determinants among the investigated biomarkers, providing insights into the DPH toxicity in crayfish. This study brought the first insight into utilising the fluorogenically active substrates BFC and DBF to demonstrate the CYP involvement in the detoxification metabolism in marbled crayfish. Further, our results provided information on valuable antioxidant defence mechanisms and biomarker responses for a future DPH toxicity assessment in aquatic organisms.
Keywords: cytochrome P450 • oxidative stress • biomarker • aquatic invertebrate • antihistamine
My usual Google alerts for marbled crayfish are usually misses, but this immediately caught my eye:
Transcript:
What if I told you a crayfish could clone itself and feed a nation? Welcome to the marbled crayfish saga.
Back in 1995 a reproductive accident in an aquarium created the marbled crayfish, a
freshwater Houdini that can clone itself. (That year is the first unambiguous record, not when the species originated, which was probably some time before that. And the origin may not have been an “accident in an aquarium.” This is unknowable. - ZF)
Sounds like sci-fi, right? This little critter with its army of identical offspring spread rapidly across continent in Tanzania where protein sources can be scarce and expensive. This invasive species turned into an unexpected hero. Locals quickly figured out that the marbled crayfish is not just easy to catch but also packed with nutrients. Talk about turning lemons into lemonade.
So from an accidental aquarium escapade to a cheap protein source for Tanzanians, the marbled crayfish is redefining what it means to be an invasive species. Nature enthusiasts, keep an eye out. This crayfish is making waves, one clone at a time.
If so, this would be the first record of marbled crayfish in Tanzania. But several things about this video make me skeptical.
The video has no references, so the source of this information is unknown. The last big review of crayfish introductions in Africa (Madzivanzira et al. 2020) makes only only mention of Tanzania:
(A)necdotal records suggest that P. clarkii may have established in the Kagera River, which enters Lake Victoria on the Uganda–Tanzania border.
I find it hard to believe that marbled crayfish are so widespread in Tanzania that there is no record in the scientific literature or anywhere else that I can find. (A Google search first brings up pictures of Tasmanian crayfish, so sure is the search engine that I must have meant Australia and not Africa.) It sounds like Tanzania has maybe been confused with Madagascar, where marbled crayfish are well established.
This crayfish clips show many species that are almost certainly not marbled crayfish. Only the very first shot seems to be marbled crayfish; the remainder seem to be Louisiana red swamp crayfish (Procambarus clarkii) and some other north American species (maybe Orconectes rusticus?).
Finally, the video implies, “How big a problem is it really if people can eat them?” I hate that this implies that we don’t have to take invasive species seriously.
Edit, 13 September 2024: The creator admitted this was suppressed to be Madagascar, not Tanzania. There’s a new video with the correct country.
Madzivanzira TC, South J, Wood LE, Nunes AL, Weyl OLF. 2020. A review of freshwater crayfish introductions in Africa. Reviews in Fisheries Science & Aquaculture 29(2): 218-241. https://doi.org/10.1080/23308249.2020.1802405
Marbled Crayfish: From Aquarium Accident to Tanzania's Protein Powerhouse!
