28 April 2024

Marmorkrebs on Great Lakes Now

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.

External links

Warning waters and mutant crayfish

Marbled crayfish raises eyebrows, and concerns

08 April 2024

Yanai and colleagues 2024

BioInvasion Records cover
Yanai Z, Guy-Haim T, Kolodny O, Levitt-Barmats Ya, Mazal A, Morov AR, Sagi A, Truskanov N, Milstein D. 2024. An overview of recent introductions of non-native crayfish (Crustacea, Decapoda) into inland water systems in Israel. BioInvasions Records 13(1): 195-208. https://doi.org/10.3391/bir.2024.13.1.17


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.

KeywordsCherax quadricarinatusProcambarus clarkiiProcambarus virginalis • aquarium release • invasive species • Levant

Open access

21 February 2024

Minnesota bans Marmorkrebs

Map highlighting Minnesota in US.
Minnesota has become the latest North American jurisdiction to ban Marmorkrebs. Effective yesterday (20 February 2024):

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.

External links

News release: Minnesota DNR classifies 13 invasive plants, animals as prohibited – Minnesota Department of Natural Resources

13 new 'high-risk' invasive species prohibited in MinnesotaBring 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

28 January 2024

Legrand and colleagues 2023

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.

Open access

Neculae and colleagues 2024

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.

Slusar and colleagues, 2023

Cover to Scientific Horizons
Slusar M, Muzhenko A, Kovalchuk I, Borshchenko V, Verbelchuk T. 2023. Study of the embryonic period of female crayfish egg development in different species. Scientific Horizons 26(12): 22-31. https://doi.org/10.48077/scihor12.2023.22


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 quadricarinatusProcambarus clarkii • Procambarus fallax forma virginali (sic) • Cherax destructor • reproductive female qualities

26 December 2023

Göpel and Burggren 2024

Comparative Biochemistry and Physiology cover
Göpel T, Burggren WW. 2024. Temperature and hypoxia trigger developmental phenotypic plasticity of cardiorespiratory physiology and growth in the parthenogenetic marbled crayfish, Procambarus virginalis Lyko, 2017. Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology 288: 111562. https://doi.org/10.1016/j.cbpa.2023.111562


Attempting to differentiate phenotypic variation caused by environmentally-induced alterations in gene expression from that caused by actual allelic differences can be experimentally difficult. Environmental variables must be carefully controlled and then interindividual genetic differences ruled out as sources of phenotypic variation. We investigated phenotypic variability of cardiorespiratory physiology as well as biometric traits in the parthenogenetically-reproducing marbled crayfish Procambarus virginalis Lyko, 2017, all offspring being genetically identical clones. Populations of P. virginalis were reared from eggs tank-bred at four different temperatures (16, 19, 22 and 25 °C) or two different oxygen levels (9.5 and 20 kPa). Then, at Stage 3 and 4 juvenile stages, physiological (heart rate, oxygen consumption) and morphological (carapace length, body mass) variables were measured. Heart rate and oxygen consumption measured at 23 °C showed only small effects of rearing temperature in Stage 3 juveniles, with larger effects evident in older, Stage 4 juveniles. Additionally, coefficients of variation were calculated to compare our data to previously published data on P. virginalis as well as sexually-reproducing crayfish. Comparison revealed that carapace length, body mass and heart rate (but not oxygen consumption) indeed showed lower, yet notable coefficients of variation in clonal crayfish. Yet, despite being genetically identical, significant variation in their morphology and physiology in response to different rearing conditions nonetheless occurred in marbled crayfish. This suggests that epigenetically induced phenotypic variation might play a significant role in asexual but also sexually reproducing species.