Poirier and colleagues 2026

Poirier LA, Pratt CJ, Hope E, Kingsbury S, McAlpine DF, LeBlanc F, Burbidge C. 2026. First record of the nonindigenous crayfish, Procambarus virginalis Lyko, 2017, in Nova Scotia, Canada. BioInvasions Records 15(2): 393-402. https://doi.org/10.3391/bir.2026.15.2.14

Abstract

Herein, we report the first record of the cambarid marbled crayfish (Procambarus virginalis Lyko, 2017) in the province of Nova Scotia, Canada. Originating from the pet trade in Germany, the marbled crayfish is a parthenogenic species that is known to be a rapid colonizer of multiple habitat types and can outcompete native species. Multiple collections of specimens were made during 2023 and 2024 in two small backyard ponds in the southwestern area of the province. Genetic confirmation was completed by sequencing a portion of the mitochondrial cytochrome c oxidase subunit 1 (CO1) gene using universal marine invertebrates PCR primers. A 100% match was obtained to publicly available DNA reference sequences. This species represents a potential threat to Nova Scotian waterways, as disruptions to food web organization are anticipated. With limited options for eradication and control, the potential for the mitigation or reversal of invasion impacts is low.

Keywords: marbled crayfish • range expansion • crawfish • introduction • vectors 

 

Mengal and colleagues, 2026

Mengal K, Kor G, Siino V, Levander F, Niksirat H. 2026. Effects of acute cold and heat shocks on the protein profile of crayfish hemolymph: Implications for crustacean adaptation to thermal stress. Aquaculture Reports 46: 103265. https://doi.org/10.1016/j.aqrep.2025.103265

 

Abstract

 

Temperature, a key environmental stressor, can induce changes at the molecular levels in the body of living beings, which are necessary for adaptation and survival under altered conditions. We investigated the effects of acute cold (3 °C) and heat (32 °C) shocks on hemolymph protein profiles in marbled crayfish. Results showed that cold shock induced a metabolic shift toward glucose production by increasing enzymes for breaking down glycogen and upregulating enzymes related to glycolysis, such as glycogen phosphorylase, glyceraldehyde-3-phosphate dehydrogenase, enolase, and L-lactate dehydrogenase in the hemolymph of crayfish. The upregulation of proteins such as filamin-A, alpha-actinin, and tubulin beta may indicate that immune cells in the hemolymph strengthen their survival during cold stress through reinforcement of the cytoskeletal rigidity. Shifts in the abundance of immunity-related proteins such as masquerade-like and β-1,3-glucan-binding proteins suggest that the immune system of decapods can adapt to thermal stresses via remodeling the extracellular matrix and pattern recognition receptors, ultimately modulating host defense strategies by shifting between phagocytosis and melanization. Furthermore, the regulation of reproduction-associated proteins indicates that thermal shock may affect the capacity for reproduction. These findings offer insight into how decapods cope with thermal stresses and may support strategies to protect them in farmed environments, especially under climate change. Data are available via ProteomeXchange with identifier PXD065043. 

Keywords: decapod • proteomics • temperature • marbled crayfish • thermal stress

Balzani and colleagues 2025

Balzani P, Musil M, Weiperth A, Bláha M, Kubec J, Ruokonen TJ, Ercoli F, Bányai ZM, Buřič M, Veselý L, Kouba A. 2025. Seasonal changes in trophic ecology of co-occurring freshwater invasive species at a thermal locality. Hydrobiologia 852(17): 4493-4512. https://doi.org/10.1007/s10750-025-05872-8

Abstract

We investigated the trophic ecology of three non-native crayfish species (the marbled crayfish Procambarus virginalis, the red swamp crayfish Procambarus clarkii and the spiny-cheek crayfish Faxonius limosus) and two non-native fishes (the eastern mosquitofish Gambusia holbrooki and the three-spined stickleback Gasterosteus aculeatus) from two sections of a thermal tributary of the Barát brook in Budapest (Hungary) over the four seasons using carbon and nitrogen stable isotope analysis. All crayfish species occupied an omnivore trophic position in almost all sections and seasons. On the other hand, both fishes had a predatory trophic position, with G. aculeatus occupying a higher position than G. holbrooki. These patterns are confirmed by the results of the mixing models, showing spatial and temporal changes in the diet composition. We also found interspecific differences in the crayfish trophic niche in both sections during summer and overlapped niches in the other occasions, while fish had always segregated niches. Crayfish showed interseasonal differences in the trophic niche in both sections, while fish showed seasonal niche shifts only in the upper section. Our results show a considerable plasticity in the trophic ecology of the studied non-native populations, suggesting that the temperature variability gradient has no important role in determining their trophic niche. 

Keywords: Alien species • invasive species • stable isotopes • freshwater ecology • competition • predation

 

 

Art of invasive species

From Bluesky user charlie comes these art pieces of four invasive species, with Marmorkrebs in the middle:

 

 

The other three invasives are apple snails, round gobies, and European water chestnut plants.

Marin and colleagues, 2025

Marin IN, Statkevich SV. 2025. The first discovery of the invasive marbled crayfish Procambarus fallax (Hagen, 1870) in Crimea. Arthropoda Selecta 34(3): 359–364. https://kmkjournals.com/journals/AS/AS_Index_Volumes/AS_34/AS_34_3_359_364

Abstract

Data on the discovery of the invasive marbled crayfish Procambarus fallax (Hagen, 1870) (Decapoda: Cambaridae) in the western Crimea, in the lower streams of the Alma and Belbek rivers, is presented. This is the first report of its presence on the peninsula, adding another invasive species to the list in the Russian Federation. Phylogenetic analysis reveals that the crayfish found in Crimea share the same genetic haplotype as other invasive subpopulations from Europe, Sweden, Japan, and parts of Florida. The European subpopulation has a single haplotype, suggesting a relatively recent introduction, likely from a single parent within its native range in Florida. In the case of the lower reaches of the Alma and Belbek rivers, we propose a hypothesis based on the possible involvement of large migratory birds, such as hissing swans and ducks, and plants attached to their paws in the spread of juvenile crayfish to nearby water reservoirs.

Keywords: invasion • Decapoda • Crustacea • crayfish • COI mtDNA • Crimean Peninsula

Toutain and colleagues 2025

Toutain M, Soto I, Oficialdegui FJ, Balzani P, Cuthbert RN, Huber AF, Haubrock PJ, Kouba A. 2025. Claw loss and the prey preferences of an invasive crayfish. NeoBiota 100: 91-108. https://doi.org/10.3897/neobiota.100.149248

 

Abstract

 

Predator-prey relationships underpin the stability of ecosystems but can be perturbed by numerous factors, such as biological invasions. Crayfish readily colonize new ecosystems and their impacts can modify food webs or ecosystem functioning. However, while crayfish exert high levels of predation pressure handling prey with their claws, claw loss is also common in their populations, which could mediate prey selection pressures. Here, we investigate how the number of claws in the marbled crayfish Procambarus virginalis modulates its preferences for two different available prey: Chironomus plumosus and Gammarus fossarum. We showed that the food preference of P. virginalis was mainly for soft, less mobile prey, such as C. plumosus, with significantly fewer G. fossarum (harder, more mobile prey) being killed. This preference was largely independent of claw presence but depended on the availability of prey, with fewer G. fossarum being targeted as the number of claws decreased. Our results highlight the complexity of predator-prey ecological relationships in invaded freshwater ecosystems and show that some biotic factors, such as the quantity and type of prey available, need to be taken into account in order to better understand their role in ecosystem dynamics.

Keywords: Chironomus plumosus • choice experiment • feeding preference • Gammarus fossarum • macroinvertebrate community • prey preference • Procambarus virginalis 

 

Ložek and colleagues 2025

Ložek F, Staňová AV. 2025. Conjoined twins in marbled crayfish Procambarus virginalis Lyko, 2017 (Decapoda: Astacidea: Cambaridae). Journal of Crustacean Biology 45(2): ruaf033. https://doi.org/10.1093/jcbiol/ruaf033 

Abstract

We report the first observation of viable conjoined twins of marbled crayfish Procambarus virginalis Lyko, 2015 during postembryonal development. Two cases of hatched juveniles were identified incidentally among normal hatchlings from eggs of laboratory-stocked marbled crayfish during an experiment unrelated to the observation. In the first case, each twin had its own anteroposterior body axis with dorsal adhesion in the cephalothorax region, referring to conjoined twins pattern duplicitas completa. They lived for 37 days post-hatch in the laboratory and survived moulting into the third postembryonal stage. The second case involved conjoined twins with unequal-sized embryos that died before the first moulting. Despite the rarity of the observation, the two cases occurred close in time and among a relatively low number of eggs, suggesting that the frequency of conjoined twins should be experimentally verified, as marbled crayfish could represent a promising model for its study.

 

Keywords: None provided.