23 June 2022

Tresnakova and colleagues 2022

Logo for journal "Biology"

Tresnakova N, Kubec J, Stara A, Zuskova E, Faggio C, Kouba A, Velisek J. 2022. Chronic toxicity of primary metabolites of chloroacetamide and glyphosate to early life stages of marbled crayfish Procambarus virginalis. Biology 11: 927. https://www.mdpi.com/2079-7737/11/6/927




Degradation products of herbicides, alone and in combination, may affect non-target aquatic organisms via leaching or runoff from the soil. The effects of 50-day exposure of primary metabolites of chloroacetamide herbicide, acetochlor ESA (AE; 4 µg/L), and glyphosate, aminomethylphosphonic acid (AMPA; 4 µg/L), and their combination (AMPA + AE; 4 + 4 µg/L) on mortality, growth, oxidative stress, antioxidant response, behaviour, and gill histology of early life stages of marbled crayfish (Procambarus virginalis) were investigated. While no treatment effects were observed on cumulative mortality or early ontogeny, growth was significantly lower in all exposed groups compared with the control group. Significant superoxide dismutase activity was observed in exposure groups, and significantly higher glutathione S-transferase activity only in the AMPA + AE group. The gill epithelium in AMPA + AE-exposed crayfish showed swelling as well as numerous unidentified fragments in interlamellar space. Velocity and distance moved in crayfish exposed to metabolites did not differ from controls, but increased activity was observed in the AMPA and AE groups. The study reveals the potential risks of glyphosate and acetochlor herbicide usage through their primary metabolites in the early life stages of marbled crayfish.  


Open access


15 June 2022

SyFy article spreading the word

There’s been an uptick in my Google Alerts because of a new article about Marmorkrebs on SyFy Wire.


At first, I though the article was recycled from the big burst of coverage when the marbled crayfish genome was sequenced. A good chunk of the article discusses the 2018 paper, and it uses a press photo that came out at that time.


But as I saw back in 2018, when one popular news site does a story, many more will pick it up.


Update, 6 July 2022: Ths story got picked up on Yahoo! News. Good time for me to talk about the misleading title.


The title - “Cloned crayfish accidentally created in an aquarium are conquering the world” suggests people were actively mucking about with crayfish to accomplish something. No evidence of that.


There is zero evidence marbled crayfish were “created” in an aquarium. Again, it suggests human involvement when there was almost certainly none. Triploid (but maybe not reproductive) individuals of the sexual ancestor exist in wild. Early Marmorkrebs may have been collected from the wild and only later got a foothold in the aquarium trade, 


External links


Cloned crayfish accidentally created in an aquarium are conquering the world

01 June 2022

Marn and colleagues 2022

Conservation Physiology cover

Marn N, Hudina S, Haberle I, Dobrović A, Klanjšček T. 2022. Physiological performance of native and invasive crayfish species in a changing environment: insights from Dynamic Energy Budget models. Conservation Physiology 10(1): coac031. https://doi.org/10.1093/conphys/coac031



Crayfish are keystone species important for maintaining healthy freshwater ecosystems. Crayfish species native to Europe, such as Astacus astacus and Austropotamobius torrentium, are facing decline and are increasingly endangered by changing climate and invasions of non-native crayfish, such as Pacifastacus leniusculus and Procambarus virginalis. The success of these invasions largely depends on differences in ontogeny between the native species and the invaders and how changes in the environment will affect the ontogeny. Dynamic Energy Budget (DEB) models can be used to investigate such differences because the models capture dependence of metabolism, and therefore ontogeny, on environmental conditions. We develop DEB models for all four species and investigate key elements of ontogeny and metabolism affecting interspecific competition. We then use the DEB models to predict individual growth and reproduction in current and new conditions that are expected to arise from climate change. Although observations suggest that P. leniusculus poses the major threat to native species, our analysis identifies P. virginalis, in spite of its smaller size, as the superior competitor by a large margin—at least when considering metabolism and ontogeny. Our simulations show that climate change is set to increase the competitive edge of P. virginalis even further. Given the prospects of P. virginalis dominance, especially when considering that it is able to withstand and spread at least some crayfish plague strains that severely affect native species, additional research into P. virginalis is necessary.


Open access