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!
India Today has a nice little feature on animals that reproduce asexually. I am a little disappointed that marbled crayfish only come in at the middle of the list, but the photo they used is nice.
Numerous fish and crayfish species are invasive in freshwater ecosystems, where they interact. In this study, we performed two experiments to investigate adult three-spined stickleback Gasterosteus aculeatus predation on early juvenile invasive crayfish in Europe. The first experiment focused on evaluating predation upon early juveniles of three invasive species (the marbled crayfish Procambarus virginalis, the spiny-cheek crayfish Faxonius limosus, and the signal crayfish Pacifastacus leniusculus) with varying exposure times (one, three and six hours), revealing crayfish species-specific vulnerabilities and the role of exposure duration. Marbled and spiny-cheek crayfish juveniles were more susceptible to three-spined stickleback predation than signal crayfish. Nevertheless, larger signal crayfish suffered more damage caused by the fish predator. The second experiment assessed the role of size in predation efficiency, using three different size groups of marbled crayfish juveniles as prey of adult three-spined sticklebacks during three hours of exposure. In this second experiment, we found the predation level to be size-dependent, with the smallest group of juveniles (20-80 mg) being preyed upon the most, and the largest group (250-350 mg) the least. The efficient predation of the three-spined stickleback on large juvenile crayfish underscores its potential ecological impacts also on native crayfish.
Keywords: behavioural ecology • biological invasion • non-native crayfish • non-native fish • predation
Objectives
Crayfish plague disease, caused by the oomycete pathogen Aphanomyces astaci represents one of the greatest risks for the biodiversity of the freshwater crayfish. This data article covers the de novo transcriptome assembly and annotation data of the noble crayfish and the marbled crayfish challenged with Ap. astaci. Following the controlled infection experiment (Francesconi et al. in Front Ecol Evol, 2021, https://doi.org/10.3389/fevo.2021.647037), we conducted a differential gene expression analysis described in (Boštjančić et al. in BMC Genom, 2022, https://doi.org/10.1186/s12864-022-08571-z)
Data description
In total, 25 noble crayfish and 30 marbled crayfish were selected. Hepatopancreas tissue was isolated, followed by RNA sequencing using the Illumina NovaSeq 6000 platform. Raw data was checked for quality with FastQC, adapter and quality trimming were conducted using Trimmomatic followed by de novo assembly with Trinity. Assembly quality was assessed with BUSCO, at 93.30% and 93.98% completeness for the noble crayfish and the marbled crayfish, respectively. Transcripts were annotated using the Dammit! pipeline and assigned to KEGG pathways. Respective transcriptome and raw datasets may be reused as the reference transcriptome assemblies for future expression studies.
Keywords: freshwater crayfish • Astacus astacus • Procambarus virginalis • crayfish plague • RNA sequencing
Trophic interactions are a critical component of ecosystem stability, governing prey-predator relationships. Crayfish are involved in numerous interactions within freshwater communities and, when non-native, they can negatively impact the structure and dynamics of ecosystems. During biotic interactions or unsuccessful molts, they are able to autotomize one or more claws, which can lead to changes in ecological performance among individuals. Because crayfish claws play an important role in feeding behavior, this creates an overlooked biotic context that could influence trophic interactions and impact on prey communities. It has been shown previously that crayfish claws have a minor role in predation of slow, soft prey, but their function concerning fast hard-bodied prey remains poorly studied. Here, we investigate whether the number of claws on marbled crayfish Procambarus virginalis modulates its ecological impact (focusing on predation rate) using functional response analyses against more mobile hard-bodied prey. We showed that the number of claws in P. virginalis significantly influenced the rate of predation on the prey Gammarus fossarum, with crayfish with two claws exhibiting a higher attack rate and lower handling time than clawless individuals. In addition, we found that non-trophic interactions increased with prey density, with generally antagonistic interactions between crayfish that reduced prey risk irrespective of claw presence. The influence of biotic contexts such as claw presence, prey density and prey type, as well as consumer density, should be considered in inferences of trophic and non-trophic interactions, as well as ecological impacts of invasive species.
Keywords: functional response • Procambarus virginalis • Gammarus fossarum • non-trophic interaction strength • competition
Jurmalietis R, Grickus A, Elstina A. 2024. Marbled crayfish (Procambarus virginalis) as a promising object for aquaculture industry. Conferences of Rezekne Academy of Technologies, Environment. Technology. Resources. 12th International Scientific and Practical Conference. June 27-28, 2024, “'Vasil Levski”' National Military University, Veliko Tarnovo, Bulgaria. https://conferences.ru.lv/index.php/ETR/ETR2019/rt/printerFriendly/3287/0
Marbled crayfish / marmorkrebs, parthenogenetically reproducing decapod crustacean of pet aquarium origin conventionally has been recognized as an undesirable species since it a) is an invasive pest dangerous for aquatic ecosystem resources because of its hardiness, omnivorousness, fast growth, self-cloning abilities; b) has little commercial value for food industry. However, recently an idea has been introduced about marmorkrebs as a promising cheap protein source, which can help to fight world hunger. Accordingly, research performed at Liepaja University (Latvia) was focused on marbled crayfish farming system design issues. Research paper presented discusses marmorkrebs survival capacities in small-volume microcosm tanks (made from recycled material), under harsh abiotic conditions. Pilot research results obtained will be used to develop experimental project on low-input microcosmic indoor aquaculture for marmorkrebs.
Keywords: None provided.
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
Multisensory stimuli provide organisms with information to assess the threat present in the surroundings. The impact of the chemical predatory cues combined with experiences gained between species previously unknown to each other was not fully understood. We investigated the foraging and behaviour of naïve and experienced marbled crayfish (Procambarus virginalis) juveniles in response to the chemical signals of pumpkinseed (Lepomis gibbosus) alone, and during the active foraging on the marbled crayfish juveniles. Naïve and experienced crayfish juveniles were exposed to three different conditions: the water inlet came from 1) a tank with predator actively foraging on their conspecifics, 2) the a from tank with predator only, and 3) from an empty tank. Crayfish behaviour in arenas with food and shelter was video recorded for 4 hours. The positions of crayfish in specific zones in the arena (inlet, transition, and shelter zone) were localized every five minutes. Feed consumed was measured after the trial. The results obtained indicated that crayfish exposed to the combined stimuli avoided the inlet zone and preferred the shelter zone of the arena to a greater extent than did those crayfish exposed to predator-only cues and the control. Regardless of the stimuli, experienced crayfish showed significantly reduced foraging. Crayfish juveniles were more cautious because of previous experience rather than due to scent perception. Our findings imply that crayfish respond to threat-associated
odours with the greatest potency when visual or tactile cues are present, but previous experience with predator can cause high precaution.
Keywords: predation • crayfish • fish • kairomones • alarm cues
Stein W, DeMaegd ML, Benson AM, Roy RS, Vidal-Gadea AG. 2022. Combining old and new tricks: The study of genes, neurons, and behavior in crayfish. Frontiers in Physiology 13: 947598. https://doi.org/10.3389/fphys.2022.947598
For over a century the nervous system of decapod crustaceans has been a workhorse for the neurobiology community. Many fundamental discoveries including the identification of electrical and inhibitory synapses, lateral and pre-synaptic inhibition, and the Na+/K+-pump were made using lobsters, crabs, or crayfish. Key among many advantages of crustaceans for neurobiological research is the unique access to large, accessible, and identifiable neurons, and the many distinct and complex behaviors that can be observed in lab settings. Despite these advantages, recent decades have seen work on crustaceans hindered by the lack of molecular and genetic tools required for unveiling the cellular processes contributing to neurophysiology and behavior. In this perspective paper, we argue that the recently sequenced marbled crayfish, Procambarus virginalis, is suited to become a genetic model system for crustacean neuroscience. P. virginalis are parthenogenetic and produce genetically identical offspring, suggesting that germline transformation creates transgenic animal strains that are easy to maintain across generations. Like other decapod crustaceans, marbled crayfish possess large neurons in well-studied circuits such as the giant tail flip neurons and central pattern generating neurons in the stomatogastric ganglion. We provide initial data demonstrating that marbled crayfish neurons are accessible through standard physiological and molecular techniques, including single-cell electrophysiology, gene expression measurements, and RNA-interference. We discuss progress in CRISPR-mediated manipulations of the germline to knock-out target genes using the ‘Receptor-mediated ovary transduction of cargo’ (ReMOT) method. Finally, we consider the impact these approaches will have for neurophysiology research in decapod crustaceans and more broadly across invertebrates.
Keywords: marbled crayfish • CRISPR • tail flip • stomatogastric ganglion • marmorkrebs • giant fiber • RNAi • transgenesis
The marbled crayfish is a newly introduced invasive species in the Flanders region of Belgium, first sighted in 2017. The species has primarily been sighted in artificial ponds in urbanised areas, suggesting its introduction through the release of aquarium pets. Marbled Crayfish have not yet spread to open water systems in Belgium, presenting an opportunity to experiment with control measures within a closed system. To manage this species within the urban park pond in the municipality of Westende, a pilot study was developed. The municipality did not approve of draining the pond, and the use of chemical agents is prohibited in aquatic environments in Flanders. To comply with these restrictions, we developed an alternative management measure to decrease crayfish densities and minimise the risk of spread. A dual approach will be implemented, involving an intensive catch event followed by the introduction of two fish species, Cyprinus carpio and Lota lota to further suppress the population. Electrofishing and baited crayfish traps will be used to achieve a proportional reduction in densities at the start of the reproductive season. The introduction of fish is aims at preventing juvenile crayfish from reaching the reproductive phase, by creating a year-round predation pressure with common carp predating from spring to autumn, and burbot throughout the winter. This dual approach will be tested to
determine its effectiveness in controlling marbled crayfish densities. Preliminary results obtained after the first two phases of the study, namely population reduction and the introduction of the common carp, will be presented.
Keywords: Marbled Crayfish, invasive species management
Conjoined twins in crustaceans, including crayfish, have been predominantly observed during early developmental stages. However, cases of conjoined twins surviving into juvenile stages are infrequent and often associated with mortality resulting from complications during moulting due to morphological abnormalities. In this study, we present a unique case of marbled crayfish conjoined twins that remained viable for 36 days post-hatch, progressing into the 3rd juvenile stage with the ability to moult. The fused individuals exhibited separate complete anteroposterior body axes, conjoined along the dorsal side of the cephalothorax. Both twins demonstrated successful predation of living nauplii of Artemia salina, their provided food source. Nonetheless, reduced mobility led to the growth of epibionts on their body surface, ultimately hindering the moulting process. This exceptional case sheds light on the prolonged survival and functional capabilities of conjoined twins in crayfish, expanding our understanding of their developmental biology.
Keywords: decapods, developmental aberration, parthenogenesis, genetic anomalies
Marbled crayfish (Procambarus virginalis) is an example of a freshwater invader spreading
across Europe, and understanding its establishment and distribution is crucial. This study
aimed to assess the role of temperature in the invasion of marbled crayfish in the artificially
warm outflow channel of a power plant in Estonia. It was hypothesized that warmer water
temperature and the temperature gradient along the channel would impact crayfish
establishment, distribution, and trophic niche. Temperature loggers recorded a gradient,
revealing that the channel was significantly warmer than the reservoir, providing a suitable
habitat for crayfish. Stable isotope analyses showed spatial and seasonal trophic niche
shifts. The crayfish diet at the channel head mainly consisted of macroinvertebrates and
macrophytes, while the mouth had a diet dominated by periphyton. Additionally, the
crayfish shifted from consuming primary consumers in spring to primary producers in
autumn. Temperature played a crucial role in crayfish establishment, but other factors like
food source availability likely influenced population distribution. Overall, this research
sheds light on the importance of temperature and ecological aspects in the invasion
dynamics of marbled crayfish.
Keywords: stable isotopes • trophic niche • invasive species • population dynamic •
temperature effect
Kaliberda A, Marenkov O, Kaliberda N. 2024. The use of albuvir to produce a life-sustaining young crayfish. In: Modern Scientific and Technical Research in the Context of Linguistic Space (in English): Conference materials of the III All-Ukrainian scientific and practical conference of young scholars and students. 355 pp. Dnipro: Bila K. O. https://www.dnu.dp.ua/docs/ndc/2024/materiali_konferenc/13.pdf#page=18
(First paragraph only.)
Marbled crayfish or Marmorkrebs (Procambarus virginalis) is a perspective species in aquaculture and water areas because a single individual is only needed to establish a new population, and they can reproduce athletes. Therefore, it is important to clarify the biological aspects of its breeding and the influence of biological additives «Albuvir» on the young generation`s vitality. Albuvir is a broad-spectrum antiviral agent. The drug is a composition of acidic peptides capable of self-organization and
self-adaptation in the body. Their mechanism is based on the blockade of nuclear import peptides and prevents import from the viral genome from crossing the nuclear membrane. An interesting detail is that adaptation to the drug is impossible for the virus and for the animal organism because the drug is a quasi-living self-organizing system and its composite pharmacophore is unique for each animal and virus. Marbled crayfish is reproduced by means of parthenogenesis – an asexual reproduction in which a female can produce an embryo without fertilizing an egg with sperm. As a result, their offspring is genetically identical, which makes this species is the best research object.
Keywords: None provided.
The marbled crayfish (Procambarus virginalis) is a parthenogenetic invasive species across much of the world, and when found, euthanasia is often recommended to reduce spread to naïve ecosystems. Euthanasia recommendations in crustaceans includes a two-step method: first to produce nonresponsiveness and then to destroy central nervous tissue. Minimal data exist on adequate anesthetic or immobilization methods for crayfish. A population of 90 marbled crayfish was scheduled for euthanasia due to invasive species concerns. The population was divided into six treatment groups to evaluate whether immersion in emulsified isoflurane or propofol solutions could produce nonresponsiveness. Each group was exposed to one of six treatments for 1 h: isoflurane emulsified at 0.1%, 0.5%, 2%, 5%, and 15% or propofol at 10 mg/L and then increased to 100 mg/L. Crayfish from all treatment groups were moved to nonmedicated water after completion of 1 h and observed for an additional 4 h. All crayfish treated with isoflurane showed lack of a righting reflex at 5 min and loss of movement after 30 min. By 240 min (4 h), none of the crayfish from the isoflurane treatment groups regained movement. None of the crayfish in the propofol treatment achieved loss of reflexes or responsiveness, and all remained normal upon return to nonmedicated water. Isoflurane emulsified in water produces nonresponsiveness that is appropriate for the first step of euthanasia, while propofol was insufficient at these treatment doses.
Keywords: None provided.
Das K, Roy K, Mráz J, Buřič M, Kouba A. 2024. Considerations for fatty acids in standardized reference diet for parthenogenetic marbled crayfish Procambarus virginalis model organism. Scientific Reports 14: 15933. https://doi.org/10.1038/s41598-024-66268-7
Fatty acid accumulation was studied in the parthenogenetic all-female marbled crayfish Procambarus virginalis using six arbitrarily designed experimental feeds and related to individuals with glair glands (sexual maturity) after 100 days of ad libitum feeding at 21°C, including gravid females from the wild as a reference. Fatty acids 16:0 and 18:1n-9 comprised 40% of the total amount of fatty acids and tended to up-concentrate in bodies. Shorter chain 14:0 depleted from feed to body. Across diets, there was a concomitant decrease in precursor fatty acid and increase in product fatty acid, such as reinforcements in monounsaturated fatty acid (18:1n-9), eicosanoid precursors 20:4n-6 (arachidonic acid, ARA) and 20:5n-3 (eicosapentaenoic acid, EPA) in-vivo, but not 22:6n-3 (docosahexaenoic acid, DHA) except when deficient in CHI or CHI + SPI diets. Saturation kinetics modeling (R2 0.7–0.9, p < 0.05) showed that when the ARA share is ~ 1%, the EPA share is ~ 8%, and the DHA share is ~ 2% in the food lipids, the accumulation of fatty acids in body lipids levels off. The lowest DHA in the CHI (0% glair glands) or CHI + SPI (0–3.9% glair glands) diets, and the lowest ARA in SER (0% glair glands) or SER + SPI (0–3% glair glands) diets, were synchronous with negligible sexual maturity despite a wide range of observed specific growth rates (2.77–3.60% per day), body size (0.44–0.84 g), ≤ 5% crude lipid and 40–46% crude protein feed. The FISH and SHRIMP diets (56% protein, 11–14% lipid) with the highest ARA, EPA, and DHA together seem to be the most conducive diets for sexual maturity (up to 20% of individuals with glair glands). We propose a fatty acid profile mimicking the FISH or SHRIMP diets as a starting point for designing the lipid content required in the marbled crayfish standardized reference diet.
Keywords: None provided.
Data variability frequently complicates reproducibility and interpretation of experimental results. Such variability arises from numerous sources such as differences in procedures or not accounting for key biological factors (e.g. sex, biological rhythms, prandial state). Making the situation more problematic, variation in physiological performance is often viewed as highly labile, easily and rapidly influenced by environmental stressors, development, etc., making it diffcult to pin down a source for variation. Undeniably, however, unknown (or ignored) genetic variation among and within strains/lines can also be a significant source of data variability in published physiological measurements, though surprisingly this has not been extensively investigated as a specific source of physiological variation. We hypothesized that variation in physiological performance is correlated with the intrinsic degree of genetic variability of the subject animal. To test this hypothesis, we employed two animal models: 1) Inbred lines (e.g., NHGRI-1) derived from wild type strains of the zebrafish (Danio rerio), with an estimated 15% of the genetic heterozygosity of wild type AB zebrafish, and 2) the parthenogenetically reproducing marbled crayfish (Procambarus virginalis), all specimens of which are genetically identical clones. For these two animal models, we measured both physiological variables (e.g. heart rate, stroke volume, cardiac output, oxygen consumption) and morphological variables (e.g. yolk-chorion ratio, body mass, embryo mass, total length, condition factor, specific growth rate) during development. We subjected the two animal models to environmental stress in the form of both temperature and hypoxia to stimulate physiological responses that could be compared and contrasted among populations. From these data we then calculated the resultant coeffcients of variation for measured variables for wild type and low/zero heterozygosity populations and/or species. In zebrafish, both the wildtype AB and NHRGI-1 lines showed similar developmental trajectories characterized by similar mean values for physiological and morphological variables. Additionally, similar mean values for physiological and morphological variables were recorded in the face of temperature and hypoxia challenge. Yet, importantly, the coeffcient of variation for each measured variable was significantly lower in NHGRI-1 than AB larvae for >90% of the assessed endpoints. In the clonal crayfish, genetically identical early stage marbled crayfish reared in different temperatures or oxygen levels show major acclimation responses, but generally showed less morphological and physiological variation about the mean than sexually-reproducing species crayfish with inherently much greater genetic variation, as evident from comparisons of calculated coeffcients of variation. A key question regarding the clonal crayfish is how can there be any morphological or physiological variation between individuals? We suggest that variability that persists may arise from microenvironmental differences during rearing (e.g. egg position during incubation on the mother’s pleon) and/or stochastic differences in gene expression (e.g. due to random epimutations) in this clonal species. In conclusion, genetic diversity clearly contributes to physiological variability. For future experiments, low heterozygosity lines and/or clonal species may be useful for decreasing inter-individual variation, thus aiding interpretation of results and enhancing reproducibility. In any event, scientific documentation of physiological studies should include as much information on (genetic) background of the experimental animals as possible.
Keywords: None provided.
Note: This is the full abstract presented at the American Physiology Summit 2024 meeting. There are no additional versions or additional content available for this abstract.
An eco-monitoring programme to assess faunal biodiversity in the main rivers of the northern Iberian Peninsula (Spain) reveals the first occurrence of the marbled crayfish Procambarus virginalis (Decapoda: Cambaridae) in Iberian inland waters. Iberian specimens have been identified by combining morphological and genetic traits. We discuss the most plausible pathways and introduction vectors, its potential invasiveness and subsequent impacts on host localities. Our preliminary results raise concern about the potential threat of P. virginalis to native fauna and ecosystem dynamics, as P. virginalis was found in an area of great cultural and ecological importance with relevant populations of endangered species. Due to the invasive history of the marbled crayfish, eradication of these individuals is urgent. This study confirms the importance of early warning systems for exotic species, keeping the population, forest guards and field technicians informed about potential invasive species to execute a rapid and effective response.
Keywords: None provided.
The first ten minutes of this video from Great Lakes Now is an excellent mini-documentary on the discovery of Marmorkrebs in North America and steps taken to try to eliminate it.
There’s also a short news article.
Crayfish are known to effectively invade freshwater systems worldwide. Whilst no native crayfish species exist in Israel, three exotic species have been documented in recent years, and their introduction details are hereby discussed. Three of these introduction events, one of each species, were previously reported; one was established, one failed to establish, and the third was successfully eradicated. However, more recently, invasive crayfish have been independently detected multiple times, involving a variety of natural and artificial habitats. Altogether, three invasive crayfish species currently inhabit Israeli freshwaters: Cherax quadricarinatus, Procambarus clarkii, and Procambarus virginalis. They were found in fourteen independent cases, and at least five of them represent established populations. Similar to other crayfish invasions around the globe, we speculate that the invasive populations in Israel result from the intentional release of aquarium inhabitants, as well as from aquaculture escapees. The import and trade policy of aquatic organisms in Israel requires thorough revision to prevent future invasions. Thought should also be given to the prevention of the spread of the existing invasive populations as well as to their eradication, if possible.
Keywords: Cherax quadricarinatus • Procambarus clarkii • Procambarus virginalis • aquarium release • invasive species • Levant
It is unlawful to possess, import, purchase, transport or introduce prohibited invasive species, except under a DNR-issued permit for disposal, decontamination, control, research or education.
News release: Minnesota DNR classifies 13 invasive plants, animals as prohibited – Minnesota Department of Natural Resources
13 new 'high-risk' invasive species prohibited in Minnesota – Bring Me the News
Minnesota DNR Classifies 13 Invasive Plants + Animals As Prohibited – KFRO
Hear (sic) are Minnesota DNR’s 13 Newest High-Risk Invasive Species – KDHL
Legrand C, Andriantsoa R, Lichter P, Raddatz G, Lyko F. 2023. Time-resolved, integrated analysis of clonally evolving genomes. PLOS Genetics 19(12): e1011085. https://doi.org/10.1371/journal.pgen.1011085
Clonal genome evolution is a key feature of asexually reproducing species and human cancer development. While many studies have described the landscapes of clonal genome evolution in cancer, few determine the underlying evolutionary parameters from molecular data, and even fewer integrate theory with data. We derived theoretical results linking mutation rate, time, expansion dynamics, and biological/clinical parameters. Subsequently, we inferred time-resolved estimates of evolutionary parameters from mutation accumulation, mutational signatures and selection. We then applied this framework to predict the time of speciation of the marbled crayfish, an enigmatic, globally invasive parthenogenetic freshwater crayfish. The results predict that speciation occurred between 1986 and 1990, which is consistent with biological records. We also used our framework to analyze whole-genome sequencing datasets from primary and relapsed glioblastoma, an aggressive brain tumor. The results identified evolutionary subgroups and showed that tumor cell survival could be inferred from genomic data that was generated during the resection of the primary tumor. In conclusion, our framework allowed a time-resolved, integrated analysis of key parameters in clonally evolving genomes, and provided novel insights into the evolutionary age of marbled crayfish and the progression of glioblastoma.
Keywords: None provided.
Neculae A, Barnett ZC, Miok K, Dalosto MM, Kuklina I, Kawai T, Santos S, Furse JM, Sîrbu OI, Stoeckel JA, Pârvulescu L. 2024. Living on the edge: Crayfish as drivers to anoxification of their own shelter microenvironment. PLOS ONE 19(1): e0287888. https://doi.org/10.1371/journal.pone.0287888
Burrowing is a common trait among crayfish thought to help species deal with adverse environmental challenges. However, little is known about the microhabitat ecology of crayfish taxa in relation to their burrows. To fill this knowledge gap, we assessed the availability of oxygen inside the crayfish shelter by series of in-vivo and in-silico modelling experiments. Under modeled condition, we found that, except for the entrance region of the 200 mm, a flooded burrow microenvironment became anoxic within 8 h, on average. Multiple 12-hour day-night cycles, with burrows occupied by crayfish for 12 h and empty for 12 h, were not sufficient for refreshing the burrow microenvironment. We then examined the degree to which crayfish species with different propensities for burrowing are tolerant of self-created anoxia. From these experiments, primary and secondary burrowers showed best and most consistent tolerance—exhibiting ≥ 64% survival to anoxia and 25–91% survival of ≥ 9 h at anoxia, respectively. Tertiary burrowers exhibited little to no tolerance of anoxia with 0–50% survival to anoxia and only one species exhibiting survival (2%) of ≥ 9 h at anoxia. Results suggest that moderate to strongly burrowing crayfish can quickly draw down the dissolved oxygen in burrow water but appear to have conserved a legacy of strong tolerance of anoxia from their monophyletic ancestors–the lobsters–whereas tertiary burrowers have lost (or never evolved) this ability.
Keywords: None provided.
Freshwater crayfish farming is a promising area of production in the food market. This aquaculture industry is currently gaining popularity around the world, but given the high consumer demand, it requires modernisation. The efficiency of aquaculture production is based on the introduction of innovative methods into production processes, which are based on knowledge of biological characteristics, including reproductive capacity and the embryonic period of caviar development. The study aims to assess the reproductive quality of females and determine the incubation period of caviar, its quantity, weight, and survival rate. The study presents the results of research on the reproductive qualities and embryonic period of crayfish eggs of four species (Cherax quadricarinatus, Procambarus clarkii, Procambarus fallax forma virginalis, Cherax destructor) kept in separate closed water supply tanks at an optimal planting density of 4 individuals per 0.45 m2 . Studies have shown that the colour range of caviar and the duration of the incubation period for its maturation varies among different crayfish species. Thus, the first stage of incubation was the shortest and ranged from 2.80 (Florida crayfish) to 3.55 (destructor crayfish) days, while the second stage lasted the longest – from 13.17 to 15.80 days for Australian and broad-toed crayfish, respectively. Based on the analysis of the physiological characteristics of the female crayfish micropopulation, they were divided into quality categories, considering the following indicators: female weight, egg weight, total number of eggs, and number of eggs per 1 g of female. Females of the Australian red snapper of the excellent category was the best among all species in terms of live weight (63.0±0.67 g), egg weight (5.0±0.05 g) and total number of eggs (376.8±16.34 pcs.), the lowest similar indicators were in the marble species (16.8±0.15 g, 1.6±0.03 g, 124.5±2.66 pcs.), respectively. In terms of the number of eggs per 1 g of female weight, Florida crayfish prevailed (7.8±0.19). Instead, the destructor crayfish had intermediate results in these characteristics. The study results can be used in the economic activities of enterprises producing aquatic organisms.
Keywords: Cherax quadricarinatus • Procambarus clarkii • Procambarus fallax forma virginali (sic) • Cherax destructor • reproductive female qualities
