Artem and colleagues, 2023

Artem O, Oleh M, Iryna H. 2023.  Physiological and biochemical adaptations’ assessment of the marbled crayfish Procambarus virginalis (Lyko, 2017) as an invasive specie (sic) of Ukraine. World Scientific News 182: 57-76. http://www.worldscientificnews.com/article-in-press/2023-2/182-2023/, http://www.worldscientificnews.com/wp-content/uploads/2023/06/WSN-182-2023-57-76.pdf (direct link to PDF)

Abstract

Marbled crayfish are the typical invasive hydrobionts spreaded over the lot of world`s waterbodies and create the populations that can reproduce in the presence of only one triploid female, thereby the threat of biodiversity appears and increase the competition with local species. Due to the appearance of the marbled crayfish Procambarus virginalis (Lyko, 2017) in the open Ukrainian waterbodies, there is necessity to research it`s adaptation possibilities to the ecological factors to predict it`s possible spread and naturalization. The research aim was to determine the physiological and biochemical features of the adaptations of marbled crayfish as a new species inhabiting the aquatic ecosystems of Ukraine under the conditions of toxicological load on the aquatic ecosystem. The obtained research results indicate significant changes in individual cytological and biochemical indicators of marbled crayfish under the impact of heavy metal ions. A change in these parameters may indicate a rapid cellular response of the crustacean species to the toxic effect of heavy metals. These indicators can be used in the future in studying the adaptation of marbled crayfish in natural waterbodies.

Keywords: heavy metals • marble crayfish • physiology • adaptation

Roy and collegues 2023

Roy K, Das K, Petraskova E, Kouba A. 2023. Protein from whole-body crayfish homogenate may be a high supplier of leucine or branched-chain amino acids – A call for validation on genus Procambarus sp. Food Chemistry 427: 136728. https://doi.org/10.1016/j.foodchem.2023.136728

Abstract

Essential proteinogenic branched-chain amino acids (BCAA), particularly leucine (Leu) have been investigated for their role in enhancing human myofibrillar protein synthesis and biomedical research on tumor models. However, only a few protein sources in our current foor system have high enough BCAA or Leu coefficients (% of total amino acids) to be considered as supplements for food, sport, or biomedical research. Mostly dairy-sourced proteins such as casein and whey or rarely plant source such as maize gluten are typically regarded as the gold standards. This study hypothesized that protein isolates derived from the whole-body homogenate (including the chitinous exoskeleton) of procambarid crayfish might exhibit unusually high BCAA and Leu content. The study provides open-access data on the amino acid compositions of two procambarid crayfish (Procambarus virginalis and P. clarkii), as well as a comparison with casein. The mentioned crayfish species could offer 6.36–7.39 g Leu 100 g⁻¹ dry matter (at 43–48% protein only). Crayfish whole-body protein isolates exhibit a Leu coefficient (18.41±2.51% of total amino acids) and a BCAA coefficient (28.76±2.39% of total amino acids), which is comparable to or higher than of casein (Leu coefficient 8.65±0.08%; BCAA coefficient 20.03±0.73%). However, it is important to interpret these results with caution, due to the challenges associated with leucine and isoleucine separation, as well as potential interactions within the sample matrices. Hence, international validation of these findings is recommended.

 

Keywords: crayfish protein • human muscle protein synthesis • leucine isoleucine valine • amino acids

Kor and colleagues, 2023b

Kor G, Mengal K, Buřič M, Kozák P, Niksirat H. 2023. Granules of immune cells are the source of organelles in the regenerated nerves of crayfish antennae. Fish & Shellfish Immunology 137: 108787. https://doi.org/10.1016/j.fsi.2023.108787

 

Abstract

Regeneration refers to the regrowing and replacing of injured or lost body parts. Crayfish antennae are nervous organs that are crucial for perceiving environmental signals. Immune cells (hemocytes) are responsible for neurogenesis in crayfish. Here, we used transmission electron microscopy to investigate at ultrastructural levels the potential roles of immune cells in nerve regeneration in crayfish antennae after amputation. The results showed that, while all three types of hemocytes were observed during nerve regeneration, granules of semi-granulocytes and granulocytes are the main sources of new organelles such as mitochondria, the Golgi apparatus and nerve fibres in the regenerated nerves of crayfish antennae. We describe the transformation of immune cell granules into different organelles in the regenerating nerve at ultrastructural levels. Also, we observed that the regeneration process speeds up after crayfish moulting. In conclusion, the granules are compacted packages of versatile materials carried by immune cells and can be converted into different organelles during nerve regeneration in crayfish antennae.

Keywords: None.

Mengal and colleagues, 2023b

Mengal K, Kor G, Siino V, Buřič M, Kozák P, Levander F, Niksirat H. 2023. Quantification of proteomic profile changes in the hemolymph of crayfish during in vitro coagulation. Developmental & Comparative Immunology 147: 104760. https://doi.org/10.1016/j.dci.2023.104760

Abstract

Hemolymph is the circulatory fluid that fills the body cavity of crustaceans, analogous to blood in vertebrates. Hemolymph coagulation, similar to blood clotting in vertebrates, plays a crucial role in wound healing and innate immune responses. Despite extensive studies on the clotting process in crustaceans, no comparative quantitative analysis of the protein composition of non-clotted and clotted hemolymph in any decapod has been reported. In this study, we used label-free protein quantification with high-resolution mass spectrometry to identify the proteomic profile of hemolymph in crayfish and quantify significant changes in protein abundances between non-clotted and clotted hemolymph. Our analysis identified a total of two-hundred and nineteen proteins in both hemolymph groups. Furthermore, we discussed the potential functions of the top most high and low-abundant proteins in hemolymph proteomic profile. The quantity of most of the proteins was not significantly changed during coagulation between non-clotted and clotted hemolymph, which may indicate that clotting proteins are likely pre-synthesized, allowing for a swift coagulation response to injury. Four proteins still showed abundance differences (p < 0.05, fold change>2), including C-type lectin domain-containing proteins, Laminin A chain, Tropomyosin, and Reverse transcriptase domain-containing proteins. While the first three proteins were down-regulated, the last one was up-regulated. The down-regulation of structural and cytoskeletal proteins may affect the process of hemocyte degranulation needed for coagulation, while the up-regulation of an immune-related protein might be attributed to the phagocytosis ability of viable hemocytes during coagulation.

 

Keywords: None.

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.

 

CrayIT 2023 meeting

CrayfIT is a regional Europoean crayfish meeting that will be held this September.

The meeting will be held at the University of Pavia.

Besides the usual talks and posters, there will be a field trip to the North-Western Apennines to see visit lowland sites for Procambarus clarkii and hilly sites for Austropotamobius pallipes.

Early bird registration deadline is 2 May.

External links

CrayfIT meeting site
 

Aigner 2022

Aigner K. 2022. Ecology of marbled crayfish and possible management measures at fishing ponds in Salzburg. Master’s thesis, Department of Environment and Biodiversity, University of Salzburg. https://resolver.obvsg.at/urn:nbn:at:at-ubs:1-36654

Abstract

Exotic crayfish species are threatening native freshwater ecosystems as well as native crayfish species by affecting all trophic levels of a system, competition and being a vector of the crayfish plague pathogen. The highly invasive marbled crayfish (Procambarus virginalis) is very successful in establishing populations in the wild, due to its parthenogenetic form of reproduction. Three established populations were found at fishing ponds in Salzburg and investigated over a period of ten weeks to shed light on habitat requirements or preferences of this species as well as evaluating and comparing methods for detection and catch. Water temperature and dissolved oxygen concentration, as well as time of the year and macrophyte cover were the main factors affecting the density of active marbled crayfish in this study. Additionally, the obtained data from observations suggests a preference of marbled crayfish for structure-rich habitats providing shelters as well as food sources. Traditional crayfish traps were the most size-selective catching method, followed by fine-meshed fish traps. Hand-catch with landing nets showed no size-selectivity. In almost all samples the eDNA analyses indicated no presence of marbled crayfish, despite numerous observations at night. The false negative results of this method were likely due to insufficient filtering volumes and a low number of sub-samples. qPCR analyses of twenty individuals showed no sign of infection with the crayfish plague pathogen (Aphanomyces astaci), hinting that the population might not have encountered this pathogen yet. The results of this study provide a first insight into the ideal habitats for marbled crayfish. However, this species is known for its high ecological plasticity, which is why further investigations are strongly recommended. Additionally, management measures to supress (sic) population growth in order to avoid a spread to other freshwater systems in close proximity should be continuously undertaken as well as monitoring regarding the infection status with the crayfish plague pathogen.

 

Keywords: Marbled crayfish • Procambarus virginalis • Austria • habitat preferences • population characteristics • management measures • eDNA • crayfish plague • invasive species