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.