Scheers and colleagues 2021

Scheers K, Brys R, Abeel T, Halfmaerten D, Neyrinck S, Adriaens T. 2021. The invasive parthenogenetic marbled crayfish Procambarus virginalis Lyko, 2017 gets foothold in Belgium. BioInvasions Records 10(2): 326-340. https://doi.org/10.3391/bir.2021.10.2.11

 

Abstract

 

In 2020, four populations of the marbled crayfish Procambarus virginalis, which is included on the list of Invasive Alien Species of Union concern, were discovered in northern Belgium. These records represent the first established populations of this invasive parthenogenetic species in the Benelux. The marbled crayfish seems well established at all sites where it was discovered. Genetic analysis confirmed the species’ identity with the obtained COI Folmer fragments being 100 percent identical to reference sequences of P. virginalis from Germany, Italy, Sweden and the Czech Republic. We proposed a single diagnostic nucleotide for unambiguous character-based species identification between P. virginalis and P. fallax. The finding of this new species through opportunistic surveys instigated by citizen science reports indicates considerable knowledge gaps on crayfish distribution in Belgium. Considering the regulated status of most species in Belgium, we advocated the further set-up of dedicated crayfish surveillance using passive and active monitoring including environmental DNA detection.

 

Keywords: invasive species, Cambaridae, non-native species, Procambarus fallax forma virginalis

Stara and colleagues 2021

Stara A, Zuskova E, Vesely L, Kouba A, Velisek J. 2021. Single and combined effects of thiacloprid concentration, exposure duration, and water temperature on marbled crayfish Procambarus virginalis. Chemosphere 273: 128463. https://doi.org/10.1016/j.chemosphere.2020.128463

Abstract

The increasing utilization of chemicals and ongoing climate change have a negative impact on aquatic ecosystems. The present study examined combined effects of water temperature, chemical concentration, and duration of exposure to the neonicotinoid thiacloprid on marbled crayfish Procambarus virginalis. Crayfish were exposed to thiacloprid at the environmental concentration of 4.50 μg L^-1 and 10% 96LC50 to marbled crayfish, 64.64 μg L^-1, at water temperature of 17 and 23°C for 28 days followed by a 28 day depuration period. No crayfish died during the experiment. Both thiacloprid concentrations at 23°C showed a synergistic effect with temperature on the biochemical indicators in haemolymph compared to those at 17°C. Both concentrations of thiacloprid at both temperatures were associated with significant differences from thiacloprid-free controls (P < 0.01) in haemolymph glucose, ammonia, calcium, inorganic phosphate, and lactate; haemolymph enzymes aspartate aminotransferase, alanine aminotransferase, creatine kinase, and alkaline phosphatase; antioxidant biomarkers superoxide dismutase, catalase, glutathione S-transferase, and reduced glutathione in hepatopancreas, muscle, and gill, and showed lipid peroxidation in hepatopancreas and muscle. Histological analyses revealed structural changes and damage to gill and hepatopancreas of exposed crayfish.

Keywords: neonicotinoid • insecticide • non-target organism • synergism • haemolymph • antioxidants

Grandjean and colleagues 2021

Grandjean F, Collas M, Uriarte M, Rousset M. 2021. First record of a marbled crayfish Procambarus virginalis (Lyko, 2017) population in France. BioInvasions Records 10(2): 341-347. https://doi.org/10.3391/bir.2021.10.2.12

 

Abstract

 

Here we report the first record of marbled crayfish Procambarus virginalis in France. In total, 34 individuals were found in a pond close to the Moselle River, coexisting with the invasive Faxonius limosus and the native Astacus astacus. Their presence seems limited to one pond of the seven located in this area, probably due to a very recent human introduction. Molecular analyses based on COI mt gene confirmed the morphological identification of captured specimens as marbled crayfish. The risk of spread to the Moselle is very high particularly during flood periods. Management recommendations are given. 

 

Keywords: invasive species • parthenogenetic crayfish • coexisting crayfish species • mitochondrial DNA

Ohio lists Marmorkrebs as “Injurious aquatic invasive species”

Ohio is the latest North American jurisdiction to regulate Marmorkrebs.

 

In a PDF dated 9 April 2021 in the file name, Marmorkrebs is designated an Injurious Aquatic Invasive Species (IAIS). The one page pamphlet notes:

 

Listed species are unlawful to possess, import, or sell unless dead and/or preserved.

However, the Department of Natural Resources list of injurious aquatic invasive species is on a page that says “Published on Jul 31, 2020” in the search results. So it’s possible that Marmorkrebs were already listed last year and the new document is just the start of publicizing the new regulation. Another PDF from Spring 2019 indicates that Ohio was planning to add marbled crayfish to the list. But it hadn’t happened yet.

It’s symptomatic of a recurring problem. I, as someone who actually cares about when new regulations about this species are passed, cannot find out when these things happen. What chance does a normal pet owner with a 10 gallon aquarium have?

External links

 

Marbled Crayfish (Marmorkrebs) Control in Ohio (PDF)

Injurious Aquatic Invasive Species

 

New website: The Perfect Invader

The Perfect Invader is a new project to examine how the introduction of Marmorkrebs in Madagascar is affecting human health. 

 

Part of the project is looking at how people are eating Marmorkrebs. Some of that has already been published (e.g., here and here).

 

A newer aspect of the project, which I’ve seen in relation to other crayfish, but not Marmorkrebs, is how the crayfish affect schistosomiasis infections.

 

Check it out!

 

External links

 

The Perfect Invader

 

Okada and colleagues 2021

Okada S, Hirano N, Abe T, Nagayama T. 2021. Aversive operant conditioning alters the phototactic orientation of the marbled crayfish. The Journal of Experimental Biology 224(6): jeb242180. https://doi.org/10.1242/jeb.242180

 

Abstract 

 

Aversive learning was applied to affect the phototactic behaviour of the marbled crayfish. Animals initially showed negative phototaxis to white light and positive taxis to blue light. Using an aversive learning paradigm, we investigated the plasticity of innate behaviour following operant conditioning. The initial rate of choosing a blue-lit exit was analysed by a dual choice experiment between blue-lit and white-lit exits in pre-test conditions. During training, electrical shocks were applied to the animals when they oriented to the blue-lit exit. Memory tests were given to analyse the orientation rate to the blue-lit exit in trials 1 h and 24 h after training and these rates were compared with the pre-test. In general, animals avoided the blue-lit exit in the memory tests. When training was done three times, the long-term memory was retained for at least 48 h, although a single bout of training was also enough to form a long-term memory. Cooling animals at 4 °C or injection of cycloheximide immediately after training altered the formation of long-term memory, but had no effect on short-term memory formation. Administration of the adenylate cyclase inhibitor SQ22536, the PKA inhibitor H89, or the CREB inhibitor KG-501 immediately after training also blocked the formation of long-term memory, but had no effect on short-term memory formation. Thus, our pharmacological behavioural analyses showed that new protein synthesis was necessary to form long-term memories and that the cAMP/PKA/CREB pathway is the main signal cascade for long-term memory formation in the marbled crayfish.

 

Keywords: None provided.

Heroes release zeroes

The Illinois-Indiana Sea Grant has started a new campaign against invasive species. The aquatic species arm of the campaign is Release Zero.

 

I particularly appreciate the point that it’s hard to be a responsible pet owner when so many providers don’t know or provide scientific names. There are hundreds of species of crayfish with different invasive potential, so just selling “crayfish” is irresponsible. There is a great need for quick, high quality ways of identifying species in the pet trade.

 

Marmorkrebs are not featured on the main webpage, but are species of concern for the Great Lakes, as the project’s Twitter account points out.

 

Wild marbled crayfish populations are established across Europe and elsewhere. They have NOT been found in the Great Lakes! 🙌 Aquarium owners, anglers and others can help keep it that way.

We need way more education on this, so I hope this campaign is very successful!

External links

 

Release Zero website