Pipinić and colleagues, 2026

Pipinić K; Marn N; Hudina S. 2026. Effects of Multiple Stressors on the Crayfish– Pathogen Dynamics in Freshwater Ecosystems – A PhD Research Plan. In: Petrović Popović P, Popović M (eds.), Book of Abstracts of 10th Faculty of Science PhD Student Symposium. University of Zagreb Faculty of Science: Zagreb. https://www.croris.hr/crosbi/publikacija/prilog-skup/947642 (Direct link to PDF of conference abstract booklet: https://www.croris.hr/crosbi/publikacija/knjiga/940582)

 

Abstract

Host–pathogen dynamics have been extensively researched in model organisms of crayfish plague (Aphanomyces astaci Schikora, 1906) and freshwater crayfish. Invasive crayfish species introduced into European freshwater ecosystems are relatively tolerant of the disease due to their long coevolutionary history. They are considered vectors of crayfish plague when introduced to novel environments. Simultaneously, native populations are being decimated because they are more susceptible to the disease. A growing body of evidence suggests that similar coevolutionary processes are emerging between European crayfish and A. astaci. Host–pathogen dynamics are a key determinant of population viability, shaped by the complex interplay among the host, the pathogen, and the environment. However, how these interactions shift under global stressors such as climate change and pollution remains largely unexplored. The response to different stressors has been studied individually for crayfish plague, the native species Astacus astacus (Linnaeus, 1758), and the invasive species Procambarus virginalis Lyko, 2017. Our study aims to test the effects of multiple stressors (temperature and microplastic pollution) on the host–pathogen dynamic. We will experimentally test the exposure of A. astacus and P. virginalis to different temperature regimes, pathogen, and microplastics mixture, as well as combinations of the three stressors, and analyse their individual and joint effects on crayfish fitness (survival, growth rate, body condition and reproductive capacity). The results of our experiments will be used to train dynamic energy budget (DEB) models for both crayfish species. At the beginning of our study, we hypothesise that multiple stressors will have a greater impact on the fitness of the native species than on that of the invasive species. With DEB models, we will be able to predict tipping points at which significant metabolic responses and possible loss of native populations are expected. Tipping points may indicate conditions that negatively affect the invasive potential of P. virginalis. This poster will present the experimental design, aim, and expected results of our study. 

 

Keywords: Aphanomyces astaci • Astacus astacus • Procambarus virginalis • modelling

Slusar and colleagues 2026

Slusar M, Muzhenko A, Kovalchuk S, Fedorovych Ye, Ishchuk O, Mamchenko V, Svitelskyi M. 2026. Comparative characteristics of physicochemical parameters of meat and biochemical composition of hemolymph in three species of crayfishes. Studia Biologica 20(2): 31-46. https://doi.org/10.30970/sbi.2002.887

Abstract

Background. Crayfish farming is a promising direction in the development of aquaculture. Compared with marine crustacean species, freshwater crayfish require lower cultivation costs, while their meat is regarded as an additive dietary delicacy with a high nutritional value. The aim of this study was to compare the morphological and physiological data (slaughter yield, taste quality, physicochemical composition of meat, and some biochemical indexes of hemolymph) of three species of adult crayfishes, i.e.Australian red claw crayfish (Cherax quadricarinatus), narrow-clawed crayfish (Astacus leptodactylus), and marbled crayfish (Procambarus fallax forma virginalis), which were cultivated in a recirculating aquaculture system.

 

Materials and Methods. Organoleptic and physicochemical methods were used to assess meat quality, while biochemical methods were applied to determine hemolymph parameters in the abovementioned crayfish species.

 

Results. The results showed that the edible portion relative to live weight was 15.16 ± 0.20 % in the Australian redclaw crayfish, 12.16 ± 0,21 % in the Marbled crayfish, and 9.40 ± 0,19 % in the Narrow-clawed crayfish. The highest protein content in meat was observed in marbled crayfish (17.4 ± 0.84 %). The highest fat content was registered in Australian redclaw crayfish (0.95 ± 0.024 %); for the marble crayfish, this value was 0.9 ± 0.03 %, and for the narrow-clawed crayfish, it was 0.9 ± 0.35 %. No
differences were found in carbohydrate content among the studied species; the value of this parameter was approximately 1.2 ± 0.02 % in all the crayfish species. The meat of Australian redclaw crayfish exhibited the highest energy value (76.1 ± 3.12 kcal/100 g), exceeding that of the other species by 1.3 – 2.2 kcal/100 g, marbled crayfish – 74.8 ± 3.69 kcal/100 g, and narrow-clawed crayfish ‒ 73.9 ± 3.52 kcal/100 g, respectively. In terms of hemolymph protein content, Australian redclaw crayfish showed the highest level (77.1 ± 2.87 g/L), for the narrow-clawed crayfish, this value was (64.9 ± 2.90 g/L), and for the marbled crayfish, it was (57.2 ± 2.41 g/L).

 

The highest calcium concentration in hemolymph was observed in narrow-clawed crayfish (9.52 ± 0.212 mmol/L), while comparable levels were recorded in Australian redclaw (7.99 ± 0.215 mmol/L) and marbled crayfish (7.42 ± 0.292 mmol/L). Differences in all studied indicators were considered statistically significant at p ≤ 0.05.

 

Conclusions. The study results obtained for Australian red claw crayfish, narrow-clawed crayfish and marbled crayfish allow us to evaluate their productivity and meat nutritional validity, as well as to propose the reference ranges of key indexes which can be used in optimizing aquaculture technologies and production of high-quality delicacies or supporting food products.

 

Keywords: crayfish aquaculture • Australian red claw crayfish (Cherax quadricarinatus) • narrow-clawed crayfish (Astacus leptodactylus) • marbled crayfish (Procambarus fallax forma virginalis) • slaughter yield • meat productivity • hemolymph • reference indexes

 

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